Editing Interstate 90 (section)

==Route description==
{{lengths table|length_ref=<ref name="FHWA-Routes"/>}}
|-
|[[Interstate 90 in Washington|{{abbr|WA|Washington}}]]
|{{convert|296.92|mi|km|disp=table}}
|-
|[[Interstate 90 in Idaho|{{abbr|ID|Idaho}}]]
|{{convert|73.55|mi|km|disp=table}}
|-
|[[Interstate 90 in Montana|{{abbr|MT|Montana}}]]
|{{convert|552.46|mi|km|disp=table}}<!--Includes 7.65 mi with I-15-->
|-
|[[Interstate 90 in Wyoming|{{abbr|WY|Wyoming}}]]
|{{convert|208.80|mi|km|disp=table}}
|-
|[[Interstate 90 in South Dakota|{{abbr|SD|South Dakota}}]]
|{{convert|412.76|mi|km|disp=table}}
|-
|[[Interstate 90 in Minnesota|{{abbr|MN|Minnesota}}]]
|{{convert|275.70|mi|km|disp=table}}
|-
|[[Interstate 90 in Wisconsin|{{abbr|WI|Wisconsin}}]]
|{{convert|187.13<ref name="WisDOT">{{cite book |author= Southwest Region Staff |title= State Trunk Highway Log for Southwest Region |date= December 31, 2008 |publisher= Wisconsin Department of Transportation |location=Madison, WI |type= XLS |at= 090E}}</ref>
|mi|km|disp=table}}
|-
|[[Interstate 90 in Illinois|{{abbr|IL|Illinois}}]]
|{{convert|123.89|mi|km|disp=table}}<!--Includes 15.39 mi with I-94-->
|-
|[[Interstate 90 in Indiana|{{abbr|IN|Indiana}}]]
|{{convert|156.28|mi|km|disp=table}}<!--Includes 135.6 mi with I-80-->
|-
|[[Interstate 90 in Ohio|{{abbr|OH|Ohio}}]]
|{{convert|244.75|mi|km|disp=table}}<!--Includes 142.80 mi with I-80-->
|-
|[[Interstate 90 in Pennsylvania|{{abbr|PA|Pennsylvania}}]]
|{{convert|46.30|mi|km|disp=table}}
|-
|[[Interstate 90 in New York|{{abbr|NY|New York}}]]
|{{convert|385.48|mi|km|disp=table}}
|-
|[[Interstate 90 in Massachusetts|{{abbr|MA|Massachusetts}}]]
|{{convert|135.72|mi|km|disp=table}}
|-
|Total
|{{convert|3,099.74|mi|km|disp=table}}
|}

I-90 is the longest [[Interstate Highway]] in the United States, spanning {{convert|3,099.7|mi|km}} across the northern portion of the coterminous part of the country.<ref name="FHWA-Facts"/> The transcontinental freeway passes through 13 states in the [[Pacific Northwest]], [[Mountain states|Mountain West]], [[Great Plains]], [[Midwestern United States|Midwest]], and the [[Northeastern United States|Northeast]] regions of the United States.<ref name="FHWA-Facts">{{cite web |year=2010 |title=Eisenhower Interstate Highway System, Previous Facts of the Day |url=https://highways.dot.gov/highway-history/interstate-system/50th-anniversary |publisher=Federal Highway Administration |access-date=November 28, 2021 |archive-date=August 8, 2020 |archive-url=https://web.archive.org/web/20200808130349/https://www.fhwa.dot.gov/interstate/previousfacts.cfm |url-status=live }}</ref><ref name="google">{{google maps |title=Overview of Interstate 90 |url=https://www.google.com/maps/dir/47.5902689,-122.3290545/43.7992152,-99.3498824/41.8495308,-87.644372/42.6648806,-73.7289984/42.3776024,-71.0270117/@44.1147106,-105.6436969,3287233m/am=t/data=!3m2!1e3!4b1!4m13!4m12!1m5!3m4!1m2!1d-106.6246939!2d44.3328471!3s0x5335770ccdea65cf:0xc100e85f0a55d267!1m0!1m0!1m0!1m0!3e0!4e1 |accessdate=November 29, 2021}}</ref> From the [[Wisconsin]]–[[Illinois]] state line to [[Massachusetts]], approximately {{convert|760|mi|km}} of I-90 uses [[toll road|turnpikes]] and other tolled highways with the exception of segments in [[Chicago]], northeastern Ohio, [[Pennsylvania]], and [[Albany, New York]]. The toll road sections comprise 25&nbsp;percent of the freeway's total length.<ref name="FHWA-Facts"/><ref>{{cite web |author=((FHWA Office of Transportation Policy Studies)) |date=September 2009 |title=Longer Combination Vehicles on Exclusive Truck Lanes: Interstate 90 Corridor Case Study |url=https://www.fhwa.dot.gov/policy/otps/110721/sec1.cfm |publisher=Federal Highway Administration |accessdate=December 9, 2021 |archive-date=October 9, 2022 |archive-url=https://web.archive.org/web/20221009232848/https://www.fhwa.dot.gov/policy/otps/110721/sec1.cfm |url-status=live }}</ref>

According to 2011 data from the [[Federal Highway Administration]], the busiest section of I-90 is in the Chicago area, where a [[Annual average daily traffic|daily average]] of 306,574&nbsp;vehicles use the freeway. The lowest daily traffic counts on I-90 were recorded in Wyoming, where an average of 9,820&nbsp;vehicles used rural sections of the freeway.<ref>{{cite web |author=((FHWA Office of Highway Policy Information)) |date=August 2013 |title=2011 Interstate Brief: Summary of the Interstate System by State and Route Number |pages=4, 15 |url=https://www.fhwa.dot.gov/interstatebrief2011/2011interstatebrief.pdf |publisher=Federal Highway Administration |accessdate=April 3, 2022 |archive-date=October 9, 2022 |archive-url=https://web.archive.org/web/20221009232847/https://www.fhwa.dot.gov/interstatebrief2011/2011interstatebrief.pdf |url-status=live }}</ref>

===Washington===
{{Main|Interstate 90 in Washington}}
[[File:I-90 as seen from Mount Si.jpg|thumb|right|Aerial view of I-90 near [[North Bend, Washington]]|alt=Aerial view of a divided highway making two turns in a densely forested area.]]

The western terminus of I-90 is at an intersection with [[Washington State Route 519|Washington State Route&nbsp;519]] and 4th Avenue South in the [[Sodo, Seattle|SoDo]] neighborhood of [[Seattle]]. The junction is south of [[Downtown Seattle]], adjacent to the [[Port of Seattle]] and two major sports stadiums, [[Lumen Field]] and [[T-Mobile Park]].<ref>{{cite news |last=Lindblom |first=Mike |date=August 6, 2008 |title=Port clears way for I-90 link to waterfront |page=B2 |url=http://old.seattletimes.com/html/localnews/2008094653_sodo06m.html |work=[[The Seattle Times]] |url-status=dead |archive-url=https://web.archive.org/web/20180616130827/http://old.seattletimes.com/html/localnews/2008094653_sodo06m.html |archive-date=June 16, 2018 |accessdate=November 28, 2021}}</ref> The freeway travels east through an interchange with [[Interstate 5|I-5]] and around [[Beacon Hill, Seattle|Beacon Hill]] before it enters the [[Mount Baker Ridge Tunnel]] alongside the future [[2 Line (Sound Transit)|2&nbsp;Line]] of the [[Link light rail]] system, set to open in 2025.<ref name="Times-Floating">{{cite news |last=Lee |first=Jessica |date=May 11, 2017 |title=From the archives: A look back at the I-90 floating bridges before light-rail work begins |url=https://www.seattletimes.com/seattle-news/transportation/from-the-archives-a-look-back-on-i-90-floating-bridges-before-light-rail-work-begins/ |work=The Seattle Times |accessdate=November 28, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129064619/https://www.seattletimes.com/seattle-news/transportation/from-the-archives-a-look-back-on-i-90-floating-bridges-before-light-rail-work-begins/ |url-status=live }}</ref><ref>{{cite news |last=Lindblom |first=Mike |date=March 10, 2023 |title=Sound Transit will shell out millions to keep pace with construction delays |url=https://www.seattletimes.com/seattle-news/transportation/sound-transit-will-shell-out-millions-to-keep-pace-with-construction-delays/ |work=The Seattle Times |accessdate=August 23, 2023 |archive-date=August 24, 2023 |archive-url=https://web.archive.org/web/20230824065723/https://www.seattletimes.com/seattle-news/transportation/sound-transit-will-shell-out-millions-to-keep-pace-with-construction-delays/ |url-status=live }}</ref> I-90 emerges from the tunnel on a pair of [[pontoon bridge|floating bridge]]s, among the longest of their kind: the eastbound-only [[Lacey V. Murrow Memorial Bridge]] and the [[Homer M. Hadley Memorial Bridge]], which carries westbound traffic and the future light rail line.<ref name="Times-Floating"/><ref name="WSDOT-Map">{{cite WSDOT map |year=2014 |link=yes |accessdate=November 28, 2021}}</ref>

The floating bridges cross [[Lake Washington]] to [[Mercer Island, Washington|Mercer Island]], where I-90 travels through a series of tunnels under {{convert|14|acre|ha}} of parkland, including [[Aubrey Davis Park]].<ref name="Times-90Saga">{{cite news |last=Reynolds |first=Peggy |date=September 9, 1993 |title=Last link of I-90 ends 30-year saga |page=A10 |url=https://archive.seattletimes.com/archive/?date=19930909&slug=1720198 |work=The Seattle Times |access-date=November 28, 2021 |archive-date=October 5, 2021 |archive-url=https://web.archive.org/web/20211005014301/https://archive.seattletimes.com/archive/?date=19930909&slug=1720198 |url-status=live }}</ref><ref>{{cite news |last=Johnston |first=Steve |date=September 9, 1993 |title=Hey Johnston: What's that big concrete thing floating on Lake Washington? |page=1 |url=https://archive.seattletimes.com/archive/?date=19930909&slug=1720153 |work=The Seattle Times |access-date=November 28, 2021 |archive-date=October 9, 2022 |archive-url=https://web.archive.org/web/20221009232848/https://archive.seattletimes.com/archive/?date=19930909&slug=1720153 |url-status=live }}</ref> The freeway continues from the island and enters [[Bellevue, Washington|Bellevue]], the largest city of the [[Eastside (King County, Washington)|Eastside]] region, and intersects [[Interstate 405 (Washington)|I-405]] near [[Factoria, Bellevue|Factoria]]. I-90 then travels along [[Lake Sammamish]] and through [[Issaquah, Washington|Issaquah]] as it leaves the Seattle metropolitan area and ascends into the [[Cascade Range]] on the [[Mountains to Sound Greenway]], a designated [[National Heritage Area]] and [[National Scenic Byway]].<ref>{{cite web |title=Mountains to Sound Greenway National Heritage Area |url=https://www.nps.gov/places/mountains-to-sound-greenway-national-heritage-area.htm |publisher=[[National Park Service]] |accessdate=November 28, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129064619/https://www.nps.gov/places/mountains-to-sound-greenway-national-heritage-area.htm |url-status=live }}</ref> The freeway crosses [[Snoqualmie Pass]], elevation {{convert|3,022|ft|m}}, at the crest of the mountain range near a [[The Summit at Snoqualmie|ski resort]].<ref>{{cite news |last=Hill |first=Craig |date=January 10, 2014 |title=Snoqualmie opening benefits all |page=A1 |work=[[The News Tribune]] |url=https://www.newspapers.com/clip/89735243/snoqualmie-opening-benefits-all/ |via=[[Newspapers.com]] |accessdate=November 28, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129064620/https://www.newspapers.com/clip/89735243/snoqualmie-opening-benefits-all/ |url-status=live }}</ref>

From Snoqualmie Pass, I-90 follows the [[Yakima River]] into the [[Kittitas Valley]] and intersects [[Interstate 82|I-82]] in [[Ellensburg, Washington|Ellensburg]] after a brief [[concurrency (road)|concurrency]] with [[U.S. Route 97]] (US&nbsp;97). The highway crosses the [[Columbia River]] on the [[Vantage Bridge]] and turns northeast to climb the cliffs of the [[Columbia Plateau]] near [[George, Washington|George]]. After traveling east across [[Moses Lake, Washington|Moses Lake]] and the surrounding agricultural region, I-90 begins a long concurrency with [[U.S. Route 395|US&nbsp;395]] at [[Ritzville, Washington|Ritzville]] as the highways turn northeast towards [[Spokane, Washington|Spokane]]. I-90/US&nbsp;395 is joined by [[U.S. Route 2|US&nbsp;2]] through western Spokane, where it intersects [[U.S. Route 195|US&nbsp;195]]. The freeway crosses downtown Spokane on an elevated viaduct and splits from US&nbsp;2 and US&nbsp;395 to continue east across [[Spokane Valley, Washington|Spokane Valley]] towards the Idaho state line.<ref name="WSDOT-Map"/>

===Idaho===
{{Main|Interstate 90 in Idaho}}
[[File:I-90 viaduct in Wallace, ID - looking eastbound from 6th Street.jpg|thumb|right|The viaduct bypassing [[Wallace, Idaho]], opened in 1991 as one of the last sections of I-90.|alt=View underheath an elevated highway on the shores of a narrow river flanked by rocks and walls]]

I-90 traverses the [[Idaho Panhandle]] region at the north end of the state, where it connects [[Coeur d'Alene, Idaho|Coeur d'Alene]] to communities in the [[Silver Valley (Idaho)|Silver Valley]]. From the Washington state line, the freeway follows the [[Spokane River]] through [[Post Falls, Idaho|Post Falls]] and [[Huetter, Idaho|Huetter]] to the city of Coeur d'Alene, where it intersects [[U.S. Route 95|US&nbsp;95]], the state's main north–south highway.<ref>{{cite news |last=Titone |first=Julie |date=August 25, 1996 |title=Highway 95: From top to bottom, we explore Idaho's famed roadway |page=E1 |url=https://www.spokesman.com/stories/1996/aug/25/highway-95-from-top-to-bottom-we-explore-idahos/ |work=[[The Spokesman-Review]] |accessdate=November 29, 2021 |archive-date=September 14, 2023 |archive-url=https://web.archive.org/web/20230914044803/https://www.spokesman.com/stories/1996/aug/25/highway-95-from-top-to-bottom-we-explore-idahos/ |url-status=live }}</ref> I-90 then turns southeast to bypass Coeur d'Alene and travel along a series of ridges that face [[Lake Coeur d'Alene]], crossing an arm of the lake on the [[Veterans Memorial Centennial Bridge]].<ref name="google"/><ref>{{cite news |date=February 10, 2017 |title=Bennett Bay Bridge offers best of form and function |url=https://apps.itd.idaho.gov/Apps/MediaManagerMVC/transporter/2017/021017_Trans/021017_VaultBennettBayBr.html |work=The Transporter |publisher=[[Idaho Transportation Department]] |accessdate=November 30, 2021 |archive-date=October 9, 2022 |archive-url=https://web.archive.org/web/20221009232854/https://apps.itd.idaho.gov/Apps/MediaManagerMVC/transporter/2017/021017_Trans/021017_VaultBennettBayBr.html |url-status=live }}</ref>

The freeway continues east across [[Fourth of July Summit]] and descends into the Silver Valley, where it follows the [[Coeur d'Alene River]] through several small towns along the historic [[Mullan Road]]. I-90 serves the cities of [[Kellogg, Idaho|Kellogg]] and [[Wallace, Idaho|Wallace]] before it ascends into the [[Bitterroot Range]] and crosses [[Lookout Pass]], which also marks the Montana state line.<ref name="google"/>

===Montana===
{{Main|Interstate 90 in Montana}}
[[File:I-90 eastbound at Lookout Pass on the Idaho-Montana border.jpg|thumb|right|I-90 at [[Lookout Pass]] on the Idaho–Montana border|alt=A simple overpass over a divided highway seen from a grassy area on the side of the road]]

Montana has the longest section of I-90, at almost {{convert|552|mi|km}}, despite the highway only serving a portion of the state's east–west width.<ref name="FHWA-Routes"/><ref name="MT-Map">{{cite map |year=2021 |title=Montana Official Highway Map |url=https://mdt.mt.gov/travinfo/docs/2021-mt-highway-map.pdf |location=Helena |publisher=[[Montana Department of Transportation]] |scale=Scale not given |accessdate=November 29, 2021 |archive-date=December 1, 2021 |archive-url=https://web.archive.org/web/20211201004352/https://mdt.mt.gov/travinfo/docs/2021-mt-highway-map.pdf |url-status=live }}</ref> It descends from Lookout Pass along the [[St. Regis River (Montana)|St. Regis]] and [[Clark Fork River|Clark Fork]] rivers between the foothills of the Bitteroot Range and [[Coeur d'Alene Mountains]]. The freeway travels east through the [[Alberton, Montana|Alberton Gorge]] and crosses the Clark Fork River several times before it reaches the head of the [[Missoula Valley]].<ref>{{cite news |last=Gadbow |first=Daryl |date=July 22, 2004 |title=Gorgeous Gorge |page=C1 |work=[[The Missoulian]] |url=https://www.newspapers.com/clip/89736594/gorgeous-gorge/ |via=Newspapers.com |accessdate=November 29, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129085211/https://www.newspapers.com/clip/89736594/gorgeous-gorge/ |url-status=live }}</ref> After a short concurrency with [[U.S. Route 93|US&nbsp;93]], I-90 runs along the north side of [[Missoula, Montana|Missoula]] and joins [[U.S. Route 12|US&nbsp;12]] to continue southeast along the foothills of the [[Garnet Range]] and [[Sapphire Mountains]].<ref name="MT-Map"/>

After it splits from US&nbsp;12 in [[Garrison, Montana|Garrison]], the freeway turns south to traverse the [[Deer Lodge Valley]]. It then turns east to serve [[Butte, Montana|Butte]], where it overlaps with [[Interstate 15|I-15]] for {{convert|8|mi|km|spell=in}} and intersects [[Interstate 115|I-115]]. I-90 then continues southeast and crosses the [[Rocky Mountains]] and [[Continental Divide of the Americas|Continental Divide]] at [[Homestake Pass]], which is the highest point on the entire Interstate at {{convert|6329|ft|m}}.<ref>{{cite news |last=Smith |first=Mike |date=September 22, 2016 |title=Slower speed limit in works for most of Homestake Pass |page=A1 |work=[[The Montana Standard]] |url=https://www.newspapers.com/clip/89736816/slower-speed-limit-in-works-for-most-of/ |via=Newspapers.com |accessdate=November 29, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129085211/https://www.newspapers.com/clip/89736816/slower-speed-limit-in-works-for-most-of/ |url-status=live }}</ref> The freeway travels east across the [[Jefferson River|Jefferson Valley]] and passes the headwaters of the [[Missouri River]] near [[Three Forks, Montana|Three Forks]]. It then enters the [[Gallatin Valley]].<ref name="MT-Map"/><ref>{{cite news |last=Jokerst |first=Gail |date=June 10, 2001 |title=Headwaters haven: Three Forks a quaint slice of Montana's history |page=H4 |work=The Spokesman-Review |url=https://www.newspapers.com/clip/89737271/headwaters-haven-three-forks-a-quaint/ |via=Newspapers.com |accessdate=November 29, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129091500/https://www.newspapers.com/clip/89737271/headwaters-haven-three-forks-a-quaint/ |url-status=live }}</ref>

I-90 travels around [[Bozeman, Montana|Bozeman]], where it is joined by [[U.S. Route 191|US&nbsp;191]], and crosses [[Bozeman Pass]] between the [[Bridger Mountains (Montana)|Bridger]] and [[Gallatin Range|Gallatin]] mountains. At the east end of the mountains, the freeway begins to follow the [[Yellowstone River]] and is briefly concurrent with [[U.S. Route 89|US&nbsp;89]], which serves [[Yellowstone National Park]], and splits from US&nbsp;191 at [[Big Timber, Montana|Big Timber]]. I-90 continues along the Yellowstone River through [[Billings, Montana|Billings]], overlapping with [[U.S. Route 87|US&nbsp;87]] and [[U.S. Route 212|US&nbsp;212]], until it reaches [[Lockwood, Montana|Lockwood]], the western terminus of [[Interstate 94|I-94]]. The freeways split and I-90 continues east across the [[Bighorn Basin]] before it turns south near [[Hardin, Montana|Hardin]] to follow the [[Little Bighorn River]] into the [[Crow Indian Reservation]]. The highway passes [[Little Bighorn Battlefield National Monument|the site]] of the [[Battle of the Little Bighorn]] near [[Crow Agency, Montana|Crow Agency]] and continues south along the river and the [[Wolf Mountains]] into Wyoming.<ref name="MT-Map"/><ref>{{cite news |last=Pyle |first=Richard |date=August 17, 2003 |title=The victors at Little Bighorn |page=N5 |work=[[The Philadelphia Inquirer]] |url=https://www.newspapers.com/clip/89737083/the-victors-at-little-bighorn/ |via=Newspapers.com |accessdate=November 29, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129085212/https://www.newspapers.com/clip/89737083/the-victors-at-little-bighorn/ |url-status=live }}</ref>

From 1995 to 1999, there was no numbered daytime [[Speed limits in the United States|speed limit]] on rural highways in Montana, including I-90.<ref>{{cite news |last=Whitely |first=Peyton |date=December 10, 1995 |title=With a roar, Montana drops day speed limit |page=A1 |url=https://archive.seattletimes.com/archive/?date=19951210&slug=2157057 |work=The Seattle Times |accessdate=November 29, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129090327/https://archive.seattletimes.com/archive/?date=19951210&slug=2157057 |url-status=live }}</ref> The speed limit was simply defined as "reasonable and proper" as determined on a case-by-case basis by the [[Montana Highway Patrol]] until the [[Montana Supreme Court]] ruled it was unconstitutional.<ref>{{cite news |last=Robbins |first=Jim |date=December 25, 1998 |title=Montana's Speed Limit of ?? M.P.H. Is Overturned as Too Vague |page=A20 |url=https://www.nytimes.com/1998/12/25/us/montana-s-speed-limit-of-mph-is-overturned-as-too-vague.html |work=[[The New York Times]] |accessdate=November 29, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129090327/https://www.nytimes.com/1998/12/25/us/montana-s-speed-limit-of-mph-is-overturned-as-too-vague.html |url-status=live }}</ref> The maximum daytime speed limit in Montana was initially set at {{convert|75|mph|km/h|abbr=on|round=5}} in 1999 and was later raised to {{convert|80|mph|km/h|abbr=on|round=5}} in 2015.<ref>{{cite news |last=Carter |first=Troy |date=October 1, 1995 |title=Montana interstate speed limit raised to 80 mph—mostly |url=https://www.bozemandailychronicle.com/news/montana-interstate-speed-limit-raised-to-80-mph-mostly/article_7dee866c-c7ca-5002-aee3-72c6335fd1be.html |work=[[Bozeman Daily Chronicle]] |url-status=dead |archive-url=https://web.archive.org/web/20211129090331/https://www.bozemandailychronicle.com/news/montana-interstate-speed-limit-raised-to-80-mph-mostly/article_7dee866c-c7ca-5002-aee3-72c6335fd1be.html |archive-date=November 29, 2021 |accessdate=November 29, 2021}}</ref>

===Wyoming===
{{Main|Interstate 90 in Wyoming}}
[[File:Sheridan.JPG|thumb|View of southern [[Sheridan, Wyoming]], from I-90|alt=A multi-story building named the "Mill Inn" and tall grain elevator, seen from an elevated vantage point]]

I-90 serves a portion of northeastern Wyoming that is primarily rural.<ref>{{cite news |date=August 21, 2015 |title=Speed limit upped to 80 mph on part of I-90 in NE Wyoming |url=https://www.argusleader.com/story/news/2015/08/21/speed-limit-upped-mph-part-ne-wyoming/32103899/ |work=[[Argus Leader]] |location=Sioux Falls |agency=Associated Press |accessdate=November 29, 2021}}</ref> The freeway, briefly concurrent to [[U.S. Route 14|US&nbsp;14]], travels southeast along a series of creeks to [[Sheridan, Wyoming|Sheridan]] in the northeastern foothills of the [[Bighorn Mountains]]. I-90 and US&nbsp;87 split in Sheridan and travel parallel to each other to [[Fort Phil Kearny]], where they rejoin and continue south past [[Lake Desmet]] to [[Buffalo, Wyoming|Buffalo]]. The highways split again near Buffalo at a junction with [[Interstate 25|I-25]], which overlaps with US&nbsp;87 to [[Casper, Wyoming|Casper]].<ref name="WY-Map">{{cite map |author=Public Affairs Office |year=2011 |title=Wyoming Highway Map |url=https://ss-usa.s3.amazonaws.com/c/308475559/media/77046075a7b15c06968218036445366/Wyoming%20map%20side_v2.pdf |scale=1 inch = approx. 18 miles |location=Cheyenne |publisher=[[Wyoming Department of Transportation]] |via=[[Wyoming Office of Tourism]] |access-date=November 29, 2021 |archive-date=October 3, 2021 |archive-url=https://web.archive.org/web/20211003035101/https://ss-usa.s3.amazonaws.com/c/308475559/media/77046075a7b15c06968218036445366/Wyoming%20map%20side_v2.pdf |url-status=live }}</ref>

From Buffalo, the highway turns east to cross the [[Powder River Basin]], a region with several large coal mines.<ref>{{cite news |last=Learn |first=Scott |date=July 1, 2012 |title=Coal clash: The Powder River Basin, where coal is king |url=https://www.oregonlive.com/environment/2012/06/coal_clash_out_of_the_gigantic.html |work=[[The Oregonian]] |accessdate=November 29, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129094519/https://www.oregonlive.com/environment/2012/06/coal_clash_out_of_the_gigantic.html |url-status=live }}</ref> I-90 then reaches [[Gillette, Wyoming|Gillette]], where it begins a concurrency with US&nbsp;14 and [[U.S. Route 16|US&nbsp;16]] to a three-way split in [[Moorcroft, Wyoming|Moorcroft]]. The freeway continues into the [[Bear Lodge Mountains]] (part of the [[Black Hills]]) and is rejoined in [[Sundance, Wyoming|Sundance]] by US&nbsp;14, which looped north to serve the [[Devils Tower]].<ref>{{cite news |last=Eldredge |first=Kay |date=August 29, 1982 |title=The Spell of Devils Tower |at=sec. 10, p. 25 |url=https://www.nytimes.com/1982/08/29/travel/the-spell-of-devils-tower.html |work=The New York Times |accessdate=November 29, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129102103/https://www.nytimes.com/1982/08/29/travel/the-spell-of-devils-tower.html |url-status=live }}</ref> I-90/US&nbsp;14 then continues northeast to [[Beulah, Wyoming|Beulah]], where it enters [[South Dakota]].<ref name="WY-Map"/>

===South Dakota===
{{Main|Interstate 90 in South Dakota}}
[[File:CHAMBERLAIN INTERSTATE BRIDGE.jpg|thumb|right|The [[Lewis and Clark Memorial Bridge]], which carries I-90 over the [[Missouri River]] near [[Chamberlain, South Dakota]]|alt=Distant view of a simple highway bridge crossing a wide river surrounded by rolling hills free of vegetation]]

I-90/US&nbsp;14 enters South Dakota near [[Spearfish, South Dakota|Spearfish]] and travels east through prairie land, where it is briefly concurrent with [[U.S. Route 85|US&nbsp;85]]. Beyond [[Sturgis, South Dakota|Sturgis]], the freeway turns south and follows the edge of the Black Hills to [[Rapid City, South Dakota|Rapid City]], the gateway to [[Mount Rushmore]].<ref>{{cite news |last=Henry |first=Neil |date=January 3, 1987 |title=Hush of the quiet season descends on the Black Hills |url=https://www.washingtonpost.com/archive/politics/1987/01/03/hush-of-the-quiet-season-descends-on-the-black-hills/00e14802-109a-4e1e-974e-90b2b5cc838e/ |newspaper=[[The Washington Post]] |accessdate=November 29, 2021}}</ref> It then skirts the northern edge of Rapid City, which is served by spur route [[Interstate 190 (South Dakota)|I-190]], and passes [[Ellsworth Air Force Base]] while it continues east across the plains. I-90 splits from US&nbsp;14 near [[Wall, South Dakota|Wall]], home to the [[Wall Drug]] roadside attraction and located northeast of [[Badlands National Park]].<ref>{{cite news |last=Gordon |first=Kindra |date=June 11, 2006 |title=Get away from it all |page=D1 |work=[[Rapid City Journal]] |url=https://www.newspapers.com/clip/89737914/get-away-from-it-all/ |via=Newspapers.com |accessdate=November 29, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129102613/https://www.newspapers.com/clip/89737914/get-away-from-it-all/ |url-status=live }}</ref><ref name="SD-Map">{{cite map |year=2019 |title=State Highway Map of South Dakota |scale=1 inch = approx. 15.43 miles |url=https://dot.sd.gov/media/documents/CADD-Mapping/State/SD-Map_medium.pdf |location=Pierre |publisher=[[South Dakota Department of Transportation]] |accessdate=November 29, 2021 |archive-date=October 9, 2022 |archive-url=https://web.archive.org/web/20221009232847/https://dot.sd.gov/media/documents/CADD-Mapping/State/SD-Map_medium.pdf |url-status=live }}</ref>

The freeway travels southeast into the [[Buffalo Gap National Grassland]] and also passes a pair of decommissioned [[missile silo]]s that form the [[Minuteman Missile National Historic Site]].<ref>{{cite map |year=2019 |title=Motor Vehicle Use Map: Buffalo Gap National Grassland, South Dakota |url=https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fseprd701419.pdf |scale=Scale not given |location=Washington, D.C. |publisher=[[United States Forest Service]] |accessdate=November 29, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129102615/https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fseprd701419.pdf |url-status=live }}</ref><ref>{{cite news |last=Bures |first=Frank |date=March 21, 2013 |title=Spring Travel Issue: Cold War-era tourist sites feature weapons of mass attraction |url=https://www.washingtonpost.com/blogs/liveblog/wp/2013/03/21/magazine-spring-travel-issue-cold-war-era-tourist-sites-feature-weapons-of-mass-attraction/ |newspaper=The Washington Post |accessdate=November 29, 2021}}</ref> I-90 continues east along the top of a plateau that faces the [[White River (Missouri River tributary)|White River]] and passes near [[Kadoka, South Dakota|Kadoka]] and [[Murdo, South Dakota|Murdo]]. [[U.S. Route 83|US&nbsp;83]] briefly joins the highway from Murdo to [[Vivian, South Dakota|Vivian]], where it splits off to serve the state capital of [[Pierre, South Dakota|Pierre]].<ref name="SD-Map"/> It then crosses the Missouri River on the [[Lewis and Clark Memorial Bridge]] near [[Chamberlain, South Dakota|Chamberlain]] and passes a [[rest area]] which overlooks the river and includes the {{convert|50|ft|m|adj=mid}} ''[[Dignity (statue)|Dignity]]'' statue.<ref name="KELO">{{cite news |date=June 15, 2021 |title=From cowboys to missiles: Places to stop this summer on your I-90 road trip |url=https://www.keloland.com/keloland-com-original/from-cowboys-to-missiles-places-to-stop-this-summer-on-your-i-90-road-trip/ |publisher=[[KELO-TV|Keloland.com]] |accessdate=November 29, 2021 |archive-date=October 9, 2022 |archive-url=https://web.archive.org/web/20221009232850/https://www.keloland.com/keloland-com-original/from-cowboys-to-missiles-places-to-stop-this-summer-on-your-i-90-road-trip/ |url-status=live }}</ref> From Chamberlain, I-90 continues east across the plains and past several small towns near the city of [[Mitchell, South Dakota|Mitchell]]. It then reaches the [[Sioux Falls, South Dakota|Sioux Falls]] area, where it bypasses the city to the north and intersects [[Interstate 29|I-29]] and [[Interstate 229 (South Dakota)|I-229]]. I-90 leaves Sioux Falls and crosses into [[Minnesota]] near [[Brandon, South Dakota|Brandon]].<ref name="SD-Map"/>

===Minnesota===
{{Main|Interstate 90 in Minnesota}}
[[File:I90GoldenSpikeRestAreaBlueEarthMN.jpg|thumb|right|[[Historic marker]] to commemorate the completion of I-90 in 1978 near [[Blue Earth, Minnesota]]|alt=A park with several trees and picnic tables behind a plaque titled "A Golden Dedication for I-90"]]

I-90 crosses the southern portion of Minnesota and carries unsigned [[Legislative route (Minnesota)|Legislative Route 391]] across the state.<ref>{{cite web |year=2021 |title=Section 161.12: Additional Routes Added; Federal Aid |url=https://www.revisor.mn.gov/statutes/cite/161.12 |work=[[Minnesota Statutes]] |publisher=Minnesota Revisor's Office |accessdate=November 29, 2021 |archive-date=November 30, 2021 |archive-url=https://web.archive.org/web/20211130051250/https://www.revisor.mn.gov/statutes/cite/161.12 |url-status=live }}</ref> From the South Dakota border near [[Beaver Creek, Minnesota|Beaver Creek]] to [[Albert Lea, Minnesota|Albert Lea]], the freeway travels east across farmland and towns in the plains and rolling hills of the [[Buffalo Ridge]]. It also intersects several north–south highways, including [[U.S. Route 75|US&nbsp;75]] in [[Luverne, Minnesota|Luverne]], [[U.S. Route 59|US&nbsp;59]] in [[Worthington, Minnesota|Worthington]], [[U.S. Route 71|US&nbsp;71]] in [[Jackson, Minnesota|Jackson]], and [[U.S. Route 169|US&nbsp;169]] in [[Blue Earth, Minnesota|Blue Earth]]. I-90 travels around the northern outskirts of Albert Lea and intersects [[Interstate 35|I-35]] northeast of the city. It then reaches [[Austin, Minnesota|Austin]] and a brief concurrency with [[U.S. Route 218|US&nbsp;218]].<ref name="MN-Map">{{cite map |year=2021 |title=Minnesota 2021–2022 Official Highway Map |url=https://www.dot.state.mn.us/statemap/2019/Frontside_2021.pdf |scale=Scale not given |location=St. Paul |publisher=[[Minnesota Department of Transportation]] |accessdate=November 29, 2021 |archive-date=November 29, 2021 |archive-url=https://web.archive.org/web/20211129111357/http://www.dot.state.mn.us/statemap/2019/Frontside_2021.pdf |url-status=live }}</ref>

From Austin, the freeway turns northeast to head towards [[Rochester, Minnesota|Rochester]], which it bypasses to the south and intersects [[U.S. Route 63|US&nbsp;63]] and [[U.S. Route 52|US&nbsp;52]]. I-90 continues east into the hilly [[Driftless Area]] and descends from the bluffs that overlook [[Lake Onalaska]] on the [[Mississippi River]].<ref>{{cite news |last=Stoll |first=Mike |date=May 26, 2017 |title=I-90 and the face of Mower County |url=https://www.austindailyherald.com/2017/05/i-90-and-the-face-of-mower-county/ |work=[[Austin Daily Herald]] |accessdate=November 29, 2021 |archive-date=October 9, 2022 |archive-url=https://web.archive.org/web/20221009232849/https://www.austindailyherald.com/2017/05/i-90-and-the-face-of-mower-county/ |url-status=live }}</ref> It turns southeast at [[Dakota, Minnesota|Dakota]] and is joined by US&nbsp;14 until the highways split near [[La Crescent, Minnesota|La Crescent]]. I-90 turns east before it reaches La Crescent, where it crosses the Mississippi River on the [[Dresbach Bridge]] into Wisconsin.<ref name="MN-Map"/><ref name="LCT-Bridge">{{cite news |last=Hubbuch |first=Chris |date=October 21, 2016 |title=Minnesota, Wisconsin celebrate completion of I-90 bridge |url=https://lacrossetribune.com/news/local/minnesota-wisconsin-celebrate-completion-of-i-90-bridge/article_4c810c59-8678-56cb-a34a-e27ef81e07b2.html |work=[[La Crosse Tribune]] |url-access=subscription |accessdate=November 29, 2021 |archive-date=November 30, 2021 |archive-url=https://web.archive.org/web/20211130051250/https://lacrossetribune.com/news/local/minnesota-wisconsin-celebrate-completion-of-i-90-bridge/article_4c810c59-8678-56cb-a34a-e27ef81e07b2.html |url-status=live }}</ref>

===Wisconsin===
{{Main|Interstate 90 in Wisconsin}}
[[File:I 90 bridge La Crosse.jpg|thumb|upright=0.767|[[I-90 Mississippi River Bridge|I-90 Mississippi River]] bridge near [[La Crosse, Wisconsin|La Crosse]]]]

I-90 enters Wisconsin near [[La Crosse, Wisconsin|La Crosse]] and bisects [[French Island, Wisconsin|French Island]] before it reaches [[Onalaska, Wisconsin|Onalaska]]. This section is briefly concurrent to [[U.S. Route 53|US&nbsp;53]] between La Crosse and Onalaska. The freeway travels east, generally along the [[La Crosse River]], through several towns and [[Fort McCoy, Wisconsin|Fort McCoy]] before it reaches a junction with I-94 in [[Tomah, Wisconsin|Tomah]]. The two Interstates join at Tomah and travel southeast along the edge of the hills of the [[Western Upland]], following the [[Lemonweir River|Lemonweir]] and [[Wisconsin River|Wisconsin]] rivers. It passes [[Wisconsin Dells, Wisconsin|Wisconsin Dells]], situated on the [[Dells of the Wisconsin River|gorge of the same name]] and home to several [[water park]]s and [[theme park]]s.<ref>{{cite news |last=Noel |first=Josh |date=June 14, 2016 |title=A first-timer from Chicago dives into the Wisconsin Dells |url=https://www.chicagotribune.com/travel/ct-trav-0626-dells-first-timer-20160613-story.html |work=[[Chicago Tribune]] |accessdate=November 29, 2021 |archive-date=October 9, 2022 |archive-url=https://web.archive.org/web/20221009232850/https://www.chicagotribune.com/travel/ct-trav-0626-dells-first-timer-20160613-story.html |url-status=live }}</ref><ref name="WI-Map">{{cite map |year=2019 |title=Wisconsin 2019–2020 State Highway Map |scale=1 inch = approx. 13 miles |url=https://wisconsindot.gov/Documents/travel/road/hwy-maps/statemap.pdf |location=Madison |publisher=[[Wisconsin Department of Transportation]] |accessdate=November 29, 2021 |archive-date=January 29, 2022 |archive-url=https://web.archive.org/web/20220129024329/https://wisconsindot.gov/Documents/travel/road/hwy-maps/statemap.pdf |url-status=live }}</ref>

The freeway travels east from Wisconsin Dells to the [[Portage, Wisconsin|Portage]] area, where [[Interstate 39|I-39]] begins its concurrency with I-90/I-94. The highway then crosses the Wisconsin River and travels south towards [[Madison, Wisconsin|Madison]], where it forms an eastern bypass of the city. East of Madison, I-94 separates from I-39/I-90, which continues southeast through [[Edgerton, Wisconsin|Edgerton]] and [[Janesville, Wisconsin|Janesville]]. The highway turns south and enters [[Beloit, Wisconsin|Beloit]], where it intersects [[Interstate 43|I-43]] and crosses into [[Illinois]].<ref name="WI-Map"/>

===Illinois===
{{Main|Interstate 90 in Illinois}}
[[File:Highway Isometric.jpg|thumb|right|The [[Kennedy Expressway]], looking southeast towards the [[Chicago]] skyline|alt=View of the Chicago skyline, including the prominent Willis Tower, with a divided highway leading towards it]]

I-90 uses several sections of the [[Illinois Tollway]] system as it traverses the [[Northern Illinois|northeastern corner]] of the state, primarily in the [[Chicago metropolitan area]]. It enters the state from Beloit, Wisconsin, and remains concurrent to I-39 and [[U.S. Route 51|US&nbsp;51]] on the [[Jane Addams Memorial Tollway]] through the eastern outskirts of [[Rockford, Illinois|Rockford]], where the highways split off. I-90 continues on the tollway as it follows [[U.S. Route 20|US&nbsp;20]] southeast through [[Belvidere, Illinois|Belvidere]] and [[Elgin, Illinois|Elgin]] in the [[Fox Valley (Illinois)|Fox Valley]].<ref name="ILTollway-Map">{{cite map |date=January 2020 |title=Illinois Tollway 2020 Complimentary Map |at=[https://www.illinoistollway.com/documents/20184/145046/TollwayMap_01_29_2020-SideB.pdf Chicago and Vicinity] inset |url=https://www.illinoistollway.com/documents/20184/145046/TollwayMap_01_22_2020-SideA.pdf |scale=Scale not given |location=Downers Grove |publisher=[[Illinois State Toll Highway Authority]] |accessdate=November 29, 2021 |archive-date=November 30, 2021 |archive-url=https://web.archive.org/web/20211130073626/https://www.illinoistollway.com/documents/20184/145046/TollwayMap_01_22_2020-SideA.pdf |url-status=live }}</ref>

The tollway cuts through the northwestern suburbs of Chicago, where it intersects [[Interstate 290 (Illinois)|I-290]] in [[Schaumburg, Illinois|Schaumburg]] and passes the north side of [[O'Hare International Airport]]. On the east side of the airport in [[Rosemont, Illinois|Rosemont]], I-90 intersects [[Interstate 294|I-294]] and [[Interstate 190 (Illinois)|I-190]], the latter of which serves the airport's passenger terminals and marks the end of the tollway.<ref name="ILTollway-Map"/> The freeway, now named the [[Kennedy Expressway]], travels through northwestern Chicago, where the [[Blue Line (CTA)|Blue Line]] of the [[Chicago "L"|"L" rapid transit system]] runs in the median and serves several stops.<ref name="Tribune-BlueLine">{{cite news |last=Hilkevitch |first=Jon |date=December 5, 2013 |title=O'Hare Blue Line to stay open during 4-year renovation |url=https://www.chicagotribune.com/news/ct-xpm-2013-12-05-chi-4year-492m-blue-line-project-to-be-announced-today-20131205-story.html |work=Chicago Tribune |accessdate=November 29, 2021 |archive-date=October 9, 2022 |archive-url=https://web.archive.org/web/20221009230610/https://www.chicagotribune.com/ |url-status=live }}</ref> I-90 turns southeast and is rejoined by I-94 in [[Irving Park, Chicago|Irving Park]], where it gains a set of [[reversible lane|reversible express lanes]] that travel for {{convert|6.2|mi|km}} toward the [[Near West Side, Chicago|Near West Side]].<ref>{{cite news |last=Hilkevitch |first=Jon |date=August 22, 2011 |title=Drivers frustrated by Kennedy express lanes |url=https://www.chicagotribune.com/autos/ct-xpm-2011-08-22-ct-met-getting-around-0822-20110822-story.html |at=sec. 1, p. 4 |work=Chicago Tribune |accessdate=November 29, 2021 |archive-date=November 30, 2021 |archive-url=https://web.archive.org/web/20211130071337/https://www.chicagotribune.com/autos/ct-xpm-2011-08-22-ct-met-getting-around-0822-20110822-story.html |url-status=live }}</ref>

The Kennedy Expressway travels south through the Near West Side, opposite the [[Chicago River]] from the [[Chicago Loop]] (the city's central business district), and intersects I-290 again at the [[Jane Byrne Interchange]].<ref>{{cite news |last=Wronski |first=Richard |date=November 23, 2015 |title=Kennedy Expressway tops new list of nation's most congested highways |url=https://www.chicagotribune.com/news/ct-kennedy-congestion-met-20151123-story.html |work=Chicago Tribune |accessdate=November 29, 2021 |archive-date=November 30, 2021 |archive-url=https://web.archive.org/web/20211130071339/https://www.chicagotribune.com/news/ct-kennedy-congestion-met-20151123-story.html |url-status=live }}</ref> The freeway continues onto the [[Dan Ryan Expressway]] and crosses the Chicago River near [[Chinatown, Chicago|Chinatown]] and an interchange with [[Interstate 55|I-55]]. The Dan Ryan is the widest section of I-90, at 12 through lanes, and is split between [[Local–express lanes|local and express lanes]].<ref>{{cite web |date=July 27, 2010 |title=Urban Highways with the Most Lanes |url=https://www.fhwa.dot.gov/policyinformation/tables/01.pdf |publisher=Federal Highway Administration |access-date=December 3, 2021 |archive-date=January 6, 2022 |archive-url=https://web.archive.org/web/20220106214052/http://www.fhwa.dot.gov/policyinformation/tables/01.pdf |url-status=live }}</ref><ref>{{cite news |last=Hilkevitch |first=Jon |date=March 26, 2006 |title=Buckle up, it looks like a long ride |at=sec. 1, p. 10 |work=Chicago Tribune |url=https://www.newspapers.com/clip/89956956/buckle-up-it-looks-like-a-long-ride/ |via=Newspapers.com |accessdate=December 3, 2021 |archive-date=October 9, 2022 |archive-url=https://web.archive.org/web/20221009232850/https://www.newspapers.com/clip/89956956/buckle-up-it-looks-like-a-long-ride/ |url-status=live }}</ref> I-90/I-94 is joined by the [[Red Line (CTA)|"L" Red Line]] in the median of the expressway through the city's [[South Side, Chicago|South Side]],<ref name="Tribune-BlueLine"/> where it passes [[Rate Field]], the [[Illinois Institute of Technology]] campus, and [[Washington Park (Chicago park)|Washington Park]].<ref>{{cite news |last=Channick |first=Robert |date=January 31, 2017 |title=IIT sells oldest building for redevelopment |url=https://www.chicagotribune.com/business/ct-iit-redevelop-historic-building-0201-biz-20170131-story.html |work=Chicago Tribune |accessdate=November 29, 2021 |archive-date=November 30, 2021 |archive-url=https://web.archive.org/web/20211130071922/https://www.chicagotribune.com/business/ct-iit-redevelop-historic-building-0201-biz-20170131-story.html |url-status=live }}</ref> I-90 splits from the Dan Ryan Expressway in [[Englewood, Chicago|Englewood]] and turns southeast onto the tolled [[Chicago Skyway]]. The tolled Skyway travels towards the Indiana state line, which the freeway crosses near the [[Calumet River]] in the [[East Side, Chicago|East Side]].<ref name="google"/><ref name="ILTollway-Map"/>

===Indiana===
{{Main|Indiana Toll Road}}
[[File:Aetna i90.jpg|right|thumb|A section of the [[Indiana Toll Road]] (carrying I-90) in Gary, Indiana|alt=An overhead view of a divided highway with six lanes and a raised median barrier traveling through a rural area]]

The entirety of I-90 within Indiana is concurrent with the [[Indiana Toll Road]], which crosses the state's northern fringe and is mostly shared with [[Interstate 80|I-80]].<ref name="IN-Map">{{cite map |year=2021 |title=Indiana Roadway Map 2021 |url=https://www.in.gov/indot/files/2021_Roadway_Map-NEW-SIZEuseHQextendededit.pdf |publisher=[[Indiana Department of Transportation]] |scale=Scale not given |location=Indianapolis |accessdate=November 30, 2021 |archive-date=November 2, 2021 |archive-url=https://web.archive.org/web/20211102152650/https://www.in.gov/indot/files/2021_Roadway_Map-NEW-SIZEuseHQextendededit.pdf |url-status=live }}</ref> From the Illinois state line, the tollway travels south through [[Hammond, Indiana|Hammond]] and turns east to follow the [[Grand Calumet River]] through northern [[Gary, Indiana|Gary]], where it intersects [[U.S. Route 41|US&nbsp;41]] and US&nbsp;12. I-90 then crosses [[Interstate 65|I-65]] in eastern Gary and I-94 in [[Lake Station, Indiana|Lake Station]], where it begins a concurrency with I-80.<ref name="IN-Map"/>

I-94 travels northeast near the [[Lake Michigan]] shoreline from Lake Station to [[Michigan City, Indiana|Michigan City]], while the Indiana Toll Road (I-80/I-90) follows it to the south. The tollway then moves closer to the [[Michigan]]–Indiana state line and turns east, passing through the northern outskirts of [[South Bend, Indiana|South Bend]] and [[Elkhart, Indiana|Elkhart]]. In South Bend, it intersects [[U.S. Route 31|US&nbsp;31]] and passes near the [[University of Notre Dame]]. I-80/I-90 travels parallel to the state line until it reaches an interchange with [[Interstate 69|I-69]] near [[Fremont, Indiana|Fremont]], where it turns southeast. The tollway then turns east and crosses the Ohio state line near [[Angola, Indiana|Angola]].<ref name="IN-Map"/>

===Ohio===
{{Main|Interstate 90 in Ohio}}
{{See also|Ohio Turnpike}}
[[File:Ohio Turnpike exit 142.jpg|thumb|right|Aerial view of [[Ohio Turnpike]] exit 142, showing the connector between I-90 and [[Interstate 80|I-80]] on the turnpike|alt=Aerial view of a divided highway and several ramps that lead into a toll plaza]]

At the state line near [[Montpelier, Ohio|Montpelier]], I-80/I-90 transitions from the Indiana Toll Road to the [[Ohio Turnpike]], which crosses northern Ohio. The highway continues east around several rural towns as it approaches the [[Toledo, Ohio|Toledo]] area. The turnpike crosses under [[Interstate 475 (Ohio)|I-475]] in [[Maumee, Ohio|Maumee]] without an interchange; access to I-475 is instead provided through a nearby junction with US&nbsp;20. I-80/I-90 then continues southeast across the [[Maumee River]] to [[Rossford, Ohio|Rossford]] on the southern outskirts of Toledo, where it intersects [[Interstate 75|I-75]].<ref name="OH-Map">{{cite map |author=ODOT Office of Technical Services |date=April 2019 |title=Ohio Official Transportation Map |scale=1 inch = 11 miles |url=https://www.transportation.ohio.gov/static/About/maps/2019StateMap-Back.pdf |at=[https://www.transportation.ohio.gov/static/About/maps/2019StateMap-Front.pdf Cleveland] inset |location=Columbus |publisher=[[Ohio Department of Transportation]] |accessdate=November 30, 2021 |archive-date=July 14, 2021 |archive-url=https://web.archive.org/web/20210714191632/https://www.transportation.ohio.gov/static/About/maps/2019StateMap-Back.pdf |url-status=live }}</ref>

The turnpike travels southeast through a rural area near the southwest shore of [[Lake Erie]], where it passes the cities of [[Fremont, Ohio|Fremont]] and [[Sandusky, Ohio|Sandusky]]. Near Norwalk, the highway turns northeast to follow [[Ohio State Route 2|State Route&nbsp;2]] (SR&nbsp;2) and heads to [[Elyria, Ohio|Elyria]], where I-90 splits from I-80 (which remains on the turnpike). The freeway then merges with SR&nbsp;2 and continues northeast through the lakeshore suburbs west of [[Cleveland, Ohio|Cleveland]], including [[Rocky River, Ohio|Rocky River]] and [[Lakewood, Ohio|Lakewood]]. I-90 and SR&nbsp;2 separate after crossing the [[Rocky River (Ohio)|Rocky River]] and travel parallel to each other as they enter Cleveland. I-90 continues through the southwestern residential neighborhoods of Cleveland and reaches a junction with [[Interstate 71|I-71]] and [[Interstate 490 (Ohio)|I-490]] in [[Tremont, Cleveland|Tremont]], where it turns north.<ref name="OH-Map"/>

From Tremont, I-90 turns north onto the [[Innerbelt Freeway]] and crosses the [[Cuyahoga River]] into [[Downtown Cleveland]] on the [[George V. Voinovich Bridges]].<ref>{{cite news |last=Grant |first=Alison |date=November 8, 2013 |title=Inner Belt Bridge brings crowd of onlookers with cameras, babies in strollers |url=https://www.cleveland.com/metro/2013/11/inner_belt_bridge_brings_crowd.html |work=[[The Plain Dealer]] |accessdate=November 30, 2021 |archive-date=November 30, 2021 |archive-url=https://web.archive.org/web/20211130094152/https://www.cleveland.com/metro/2013/11/inner_belt_bridge_brings_crowd.html |url-status=live }}</ref> The Innerbelt skirts the south side of Downtown Cleveland, where it intersects [[Interstate 77|I-77]] near [[Progressive Field]] and turns north to bisect the [[Goodrich–Kirtland Park]] neighborhood.<ref name="google"/> Near [[Cleveland Burke Lakefront Airport]], the freeway makes a sharp, 90-degree turn (nicknamed "[[Dead Man's Curve]]" for its frequent crashes<ref>{{cite news |last=Naymik |first=Mark |date=August 3, 2021 |title=Cleveland's Dead Man's Curve not getting straightened any time soon: Mark Naymik Reports |url=https://www.wkyc.com/article/news/local/cleveland/cleveland-dead-mans-curve-not-getting-straightened-any-time-soon/95-2e73c304-f903-4045-9e9c-3a8159156344 |publisher=[[WKYC]] |accessdate=November 30, 2021}}</ref>) and rejoins SR&nbsp;2 on the [[Cleveland Memorial Shoreway]] until they split again in [[Euclid, Ohio|Euclid]]. I-90 briefly turns southeast but resumes its northeastern route after a junction with [[Interstate 271|I-271]] in [[Willoughby Hills, Ohio|Willoughby Hills]]. The freeway travels parallel to the Lake Erie shoreline through farmland and exurban towns and crosses into Pennsylvania near [[Conneaut, Ohio|Conneaut]].<ref name="OH-Map"/>

===Pennsylvania===
{{main|Interstate 90 in Pennsylvania}}

Within Pennsylvania, I-90 is non-tolled and generally travels northeast around several communities on the Lake Erie shoreline and remains entirely in [[Erie County, Pennsylvania|Erie County]].<ref name="PA-Map">{{cite map |author=PennDOT Bureau of Planning and Research |year=2020 |title=Pennsylvania Tourism and Transportation Map |url=https://gis.penndot.gov/BPR_PDF_FILES/MAPS/Statewide/otm/otmplot_web.pdf |scale=Scale not given |location=Harrisburg |publisher=[[Pennsylvania Department of Transportation]] |accessdate=November 30, 2021 |archive-date=November 30, 2021 |archive-url=https://web.archive.org/web/20211130100700/https://gis.penndot.gov/BPR_PDF_FILES/MAPS/Statewide/otm/otmplot_web.pdf |url-status=live }}</ref> It enters the state in [[Springfield Township, Erie County, Pennsylvania|Springfield Township]] and passes through rural areas along the lake shore, parallel to US&nbsp;20 and the [[Pennsylvania Route 5|Lake Road]]. The freeway then travels through the southern outskirts of [[Erie, Pennsylvania|Erie]], where it intersects [[Interstate 79|I-79]] and [[U.S. Route 19|US&nbsp;19]]. I-90 returns to the rural areas of northeastern Erie County and intersects [[Interstate 86 (Pennsylvania–New York)|I-86]] before it reaches the New York state line near the borough of [[North East, Pennsylvania|North East]].<ref name="PA-Map"/> At {{convert|46|mi|km}}, the Pennsylvania section is I-90's shortest within a single state.<ref name="FHWA-Facts"/>

===New York===
{{Main|Interstate 90 in New York}}
{{See also|New York State Thruway}}
[[File:I-90 East - Exit 27 - NY30 One Mile (49175740706).jpg|thumb|right|The [[New York State Thruway]] near [[Amsterdam, New York|Amsterdam]]|alt=A divided highway with two lanes in each direction, seen on a straightaway with trees off to the sides]]

I-90 enters New York in [[Chautauqua County, New York|Chautauqua County]] and runs concurrently with the mainline of the tolled [[New York State Thruway]]. It travels northeast along the Lake Erie shoreline between [[New York State Route 5|Lake Road]] to the north and US&nbsp;20 to the south through [[Dunkirk, New York|Dunkirk]] and [[Fredonia, New York|Fredonia]]. The highways enter the [[Buffalo, New York|Buffalo]] area, where the toll road runs north–south through [[Cheektowaga, New York|Cheektowaga]] and forms an eastern bypass, using auxiliary routes [[Interstate 190 (New York)|I-190]] and [[Interstate 290 (New York)|I-290]] to serve the city.<ref name="google"/><ref name="NYS-Map">{{cite map |year=2001 |title=New York State Map |url=http://iloveny.com/_files/map_nys_base.pdf |at=[https://web.archive.org/web/20091231053955/http://iloveny.com/_files/map_metro_albany.pdf Albany/Schenectady/Troy Metro] inset|cartography=Maps.com |scale=Scale not given |location=Albany |publisher=[[New York State Department of Economic Development]] |url-status=dead |archive-url=https://web.archive.org/web/20091231053250/http://iloveny.com/_files/map_nys_base.pdf |archive-date=December 31, 2009 |accessdate=November 30, 2021}}</ref> At a junction with I-290 near [[Buffalo Niagara International Airport]], I-90 turns east to follow the historic [[Water Level Route]] of the [[New York Central Railroad]], itself parallel to the 19th-century [[Erie Canal]].<ref name="NPS-Erie">{{cite web |year=2020 |title=Erie Canalway Map & Guide |pages=4–5 |url=http://npshistory.com/publications/erie/newspaper/2020.pdf |publisher=National Park Service |url-status=dead |archive-url=https://web.archive.org/web/20211201043819/http://npshistory.com/publications/erie/newspaper/2020.pdf |archive-date=December 1, 2021 |accessdate=November 30, 2021}}</ref><ref name="RDC-Thruway">{{cite news |last=O'Donnell |first=Harry |date=June 25, 1950 |title=Thruway to Surpass Pennsylvania Turnpike |page=13A |work=[[Rochester Democrat and Chronicle]] |url=https://www.newspapers.com/clip/89843028/thruway-to-surpass-pennsylvania-turnpike/ |via=Newspapers.com |accessdate=November 30, 2021 |archive-date=December 1, 2021 |archive-url=https://web.archive.org/web/20211201043817/https://www.newspapers.com/clip/89843028/thruway-to-surpass-pennsylvania-turnpike/ |url-status=live }}</ref>

The Thruway passes south of [[Rochester, New York|Rochester]], which it serves via a loop on [[Interstate 490 (New York)|I-490]] and the direct north–south spur [[Interstate 390 (New York)|I-390]]. I-90 travels through the [[Finger Lakes]] region and moves closer to the Erie Canal as it approaches the [[Syracuse, New York|Syracuse]] area. It travels through the city's northern outskirts, where it intersects [[Interstate 690 (New York)|I-690]], [[Interstate 81|I-81]], and [[Interstate 481|I-481]] from west to east.<ref>{{cite map |author=[[Syracuse Metropolitan Transportation Council]] |date=June 2016 |title=2016 Highway Map of Onondaga County, New York |url=http://www.ongov.net/dot/documents/2016HighwayMapofOnondagaCounty.pdf |scale=Scale not given |location=Syracuse |publisher=[[Onondaga County, New York|Onondaga County Department of Transportation]] |accessdate=November 30, 2021 |archive-date=October 9, 2022 |archive-url=https://web.archive.org/web/20221009232852/http://www.ongov.net/dot/documents/2016HighwayMapofOnondagaCounty.pdf |url-status=live }}</ref> It then continues to [[Utica, New York|Utica]], where the Thruway runs along the north side of the [[Mohawk River]] (part of the Erie Canal).<ref name="NPS-Erie"/> The section through Utica, connected to the city's downtown via [[Interstate 790|I-790]], was built between the lines of [[New York State Route 49|SR&nbsp;49]], which does not merge with the Thruway.<ref name="google"/>

I-90 then closely follows the Mohawk River southeast through several towns and villages between the foothills of the [[Catskill Mountains|Catskill]] and [[Adirondack Mountains|Adirondack]] mountains. The Thruway then reaches [[Schenectady, New York|Schenectady]], which it bypasses to the southwest and intersects [[Interstate 88 (New York)|I-88]] and [[Interstate 890|I-890]], the latter of which serves the city's downtown. The highway continues southeast into Albany to a junction with [[Interstate 87 (New York)|I-87]], where I-90 splits from the Thruway, which turns south to serve [[New York City]].<ref name="NYS-Map"/> I-90 travels east as a toll-free freeway through the northern neighborhoods of Albany and intersects [[Interstate 787|I-787]] before it crosses the [[Hudson River]]. The freeway travels south around [[Rensselaer, New York|Rensselaer]] and rejoins the Thruway via the [[Berkshire Connector]], which continues east into the [[Taconic Mountains]] toward the Massachusetts state line.<ref name="google"/><ref name="NYS-Map"/>

The [[milepost]]s and sequential [[exit number]]s on the New York State Thruway mainline originate from New York City, increasing northward on I-87 and westward on I-90;<ref name="Thruway-Exits">{{cite web |title=Interchange/Exit Listings |url=https://www.thruway.ny.gov/travelers/interchanges/index.html |publisher=[[New York State Thruway Authority]] |accessdate=November 30, 2021 |archive-date=September 8, 2021 |archive-url=https://web.archive.org/web/20210908054601/https://www.thruway.ny.gov/travelers/interchanges/index.html |url-status=live }}</ref> as a result, the mileposts and exit numbers on I-90 through most of New York run backwards compared to the federal preference for mile-based numbers increasing from west to east.<ref>{{cite news |last=Rubel |first=Abigail |date=September 27, 2021 |title=Getting There: Will New York change its highway exit numbers? |url=https://www.timesunion.com/news/article/Getting-There-Will-New-York-change-its-highway-16488756.php |work=[[Times Union (Albany)|Times Union]] |accessdate=November 30, 2021 |archive-date=December 1, 2021 |archive-url=https://web.archive.org/web/20211201045209/https://www.timesunion.com/news/article/Getting-There-Will-New-York-change-its-highway-16488756.php |url-status=live }}</ref> The Berkshire Connector uses west-to-east mileposts and exit numbers with a "B" prefix;<ref name="Thruway-Exits"/> the toll-free section of I-90 through Albany and Rensselaer uses conventional west-to-east mileposts and exit numbers despite being geographically north–south.<ref name="google"/> I-90 is currently the only Interstate that has a complete set of nine [[spur route]]s within one state, all numbers being used.<ref name="FHWA-Facts"/> In addition, [[Interstate 990|I-990]], a short spur route near Buffalo that is not directly connected to I-90, is the highest number given to an Interstate.<ref>{{cite news |date=May 31, 2006 |title=50 Years of freedom |url=https://www.overdriveonline.com/business/article/14879885/50-years-of-freedom |work=[[Overdrive (U.S. magazine)|Overdrive]] |accessdate=November 30, 2021 |archive-date=December 1, 2021 |archive-url=https://web.archive.org/web/20211201045209/https://www.overdriveonline.com/business/article/14879885/50-years-of-freedom |url-status=live }}</ref><ref>{{cite web |year=2006 |title=Tennessee's Interstate System – Frequently Asked Questions |url=https://www.tn.gov/tdot/100years-home/100years-interstate/100-years-interstate-system-faqs.html |publisher=[[Tennessee Department of Transportation]] |accessdate=November 30, 2021 |archive-date=December 1, 2021 |archive-url=https://web.archive.org/web/20211201045209/https://www.tn.gov/tdot/100years-home/100years-interstate/100-years-interstate-system-faqs.html |url-status=live }}</ref>

===Massachusetts===
{{Main|Massachusetts Turnpike}}
[[File:Fenway neighborhood seen from Prudential Skywalk.jpg|thumb|right|View of the [[Massachusetts Turnpike]] in Boston's [[Fenway–Kenmore]] neighborhood, seen from the [[Prudential Tower]]. [[Fenway Park]] is visible at top left.|alt=Aerial view of a divided highway in a dense urban neighborhood, passing under several bridges and near multi-story buildings and a baseball stadium]]

I-90 in Massachusetts is concurrent with the entirety of the [[Massachusetts Turnpike]] (also known as "the Pike" or "MassPike").<ref name="MA-Map">{{cite map |author=MassDOT Central Transportation Planning Staff |year=2019 |title=Massachusetts Official Transportation Map |scale=1 inch = 6 miles |url=https://www.mass.gov/doc/official-transportation-map-english/download |location=Boston |publisher=[[Massachusetts Department of Transportation]] |accessdate=November 30, 2021 |archive-date=December 1, 2021 |archive-url=https://web.archive.org/web/20211201060239/https://www.mass.gov/doc/official-transportation-map-english/download |url-status=live }}</ref> The turnpike begins at the New York state line in [[West Stockbridge, Massachusetts|West Stockbridge]] and travels southeast through the [[Berkshires]] to the [[Pioneer Valley]].<ref>{{cite news |last=Carlinsky |first=Dan |date=September 21, 1975 |title=...And Back Roads Of Massachusetts |at=sec. 10, p. 1 |url=https://www.nytimes.com/1975/09/21/archives/and-back-roads-of-massachusetts-fall-foliage-massachusetts.html |work=The New York Times |accessdate=November 30, 2021 |archive-date=December 1, 2021 |archive-url=https://web.archive.org/web/20211201060236/https://www.nytimes.com/1975/09/21/archives/and-back-roads-of-massachusetts-fall-foliage-massachusetts.html |url-status=live }}</ref> The highway travels through the northern suburbs of [[Springfield, Massachusetts|Springfield]], where it intersects [[Interstate 91|I-91]] and crosses the [[Connecticut River]] into [[Chicopee, Massachusetts|Chicopee]]. I-90 then crosses over [[Interstate 391|I-391]] without an interchange and serves as the northern terminus of [[Interstate 291 (Massachusetts)|I-291]] on the eastern outskirts of the city. The turnpike continues east through the hills of [[Central Massachusetts]] and serves as the eastern terminus of [[Interstate 84 (Pennsylvania–Massachusetts)|I-84]] in the town of [[Sturbridge, Massachusetts|Sturbridge]].<ref name="MA-Map"/>

From Sturbridge, the turnpike travels northeast towards [[Worcester, Massachusetts|Worcester]] and passes through the city's southern outskirts. It serves as the respective northern and western terminus of [[Interstate 395 (Connecticut–Massachusetts)|I-395]] and [[Interstate 290 (Massachusetts)|I-290]] in [[Auburn, Massachusetts|Auburn]], located southwest of Worcester, and continues to an interchange with [[Interstate 495 (Massachusetts)|I-495]] near [[Westborough, Massachusetts|Westborough]] at the edge of [[Greater Boston]]. I-90 travels through the western suburbs of Boston and travels through [[Framingham, Massachusetts|Framingham]] before it intersects [[Interstate 95|I-95]]/[[Massachusetts Route 128|Route 128]], the main beltway around Boston, on the border of [[Weston, Massachusetts|Weston]] and [[Newton, Massachusetts|Newton]].<ref name="MA-Map"/> The turnpike continues along the [[Charles River]] into Boston, where it descends into a tunnel that passes [[Boston University]], [[Fenway Park]], and [[Prudential Tunnel|under]] the [[Prudential Tower]] complex in the [[Back Bay, Boston|Back Bay]] neighborhood.<ref name="google"/><ref>{{cite news |last=Rubin |first=Eilhu |date=May 27, 2012 |title=How to look at the Prudential |url=https://www.bostonglobe.com/ideas/2012/05/26/how-look-pru/GRnscdL9VQjJQ5AsW6yXML/story.html |work=[[The Boston Globe]] |accessdate=November 30, 2021 |archive-date=December 1, 2021 |archive-url=https://web.archive.org/web/20211201060237/https://www.bostonglobe.com/ideas/2012/05/26/how-look-pru/GRnscdL9VQjJQ5AsW6yXML/story.html |url-status=live }}</ref>

I-90 intersects [[Interstate 93|I-93]] on the south side of [[Downtown Boston]] and travels under the [[Fort Point Channel]] to serve the [[Seaport District]]. The turnpike then enters the [[Ted Williams Tunnel]], which travels northeast under [[Boston Harbor]] to the passenger terminals at [[Logan International Airport]].<ref name="Globe-BigDig10">{{cite news |last=Flint |first=Anthony |date=December 29, 2015 |title=10 years later, did the Big Dig deliver? |url=https://www.bostonglobe.com/magazine/2015/12/29/years-later-did-big-dig-deliver/tSb8PIMS4QJUETsMpA7SpI/story.html |work=The Boston Globe |accessdate=November 30, 2021 |archive-date=December 5, 2020 |archive-url=https://web.archive.org/web/20201205214626/https://www.bostonglobe.com/magazine/2015/12/29/years-later-did-big-dig-deliver/tSb8PIMS4QJUETsMpA7SpI/story.html |url-status=live }}</ref> After it passes the northwest side of the airport, I-90 terminates at an interchange with [[Massachusetts Route 1A|Route 1A]] in [[East Boston]].<ref name="MA-Map"/> The section between I-93 and the airport was opened in the early 2000s as part of the [[Big Dig]] megaproject,<ref name="Globe-BigDig10"/> which rebuilt several Boston freeways and extended I-90 by {{convert|3.5|mi|km}}.<ref name="FHWA-Facts"/><ref name="MassDOT-BigDig">{{cite web |title=The Big Dig: tunnels and bridges |url=https://www.mass.gov/info-details/the-big-dig-tunnels-and-bridges |publisher=Massachusetts Department of Transportation |accessdate=November 30, 2021 |archive-date=December 1, 2021 |archive-url=https://web.archive.org/web/20211201060242/https://www.mass.gov/info-details/the-big-dig-tunnels-and-bridges |url-status=live }}</ref>