Editing Interstate 39 (section)

=== Illinois ===
[[File:Minonk,_Illinois_aerial_01A.jpg|left|thumb|Aerial view of I-39 as it passes [[Minonk, Illinois]], April&nbsp;2012]]
In Illinois, I-39 begins at [[Interstate 55 in Illinois|I-55]] north of [[Bloomington–Normal, Illinois]], less than one mile east from the intersection of I-74 and I-55 that runs around the city of Normal. US&nbsp;51 splits from I-55, joining I-39; exit&nbsp;2 marks the northern terminus of the [[U.S. Route 51 Business (Bloomington–Normal, Illinois)|US&nbsp;51 business route]]. From Normal northward, I-39 runs northward largely through rural areas. At exit&nbsp;8, the route forms the southern terminus of [[Illinois Route&nbsp;251]] (IL&nbsp;251), which was derived from the original routing of US&nbsp;51.

In [[Oglesby, Illinois|Oglesby]] in central [[LaSalle County, Illinois|LaSalle County]], I-39 passes next to [[Starved Rock State Park]], the busiest state park in Illinois. North of the park, it crosses the [[Illinois River]] over the [[Abraham Lincoln Memorial Bridge]]; at {{convert|1.3|mi|km}} long, it is the longest bridge in the state.<ref name="national_bridges2">{{cite web |author=Federal Highway Administration |title=Structure 000050019120847 |url=http://nationalbridges.com/index.php?option=com_lqm&b1849fc92c286e5b5ed0fbf618d953ae=1&task=showResults&query=8&lqm_id=169862&&format=raw&&Itemid=2 |url-status=dead |archive-url=https://web.archive.org/web/20140101034538/http://nationalbridges.com/index.php?option=com_lqm&b1849fc92c286e5b5ed0fbf618d953ae=1&task=showResults&query=8&lqm_id=169862&&format=raw&&Itemid=2 |archive-date=January 1, 2014 |access-date=June 1, 2012 |work=[[National Bridge Inventory]] |publisher=Federal Highway Administration}}</ref> Just north of the river, I-39 passes between the cities of [[LaSalle, Illinois|LaSalle]] and [[Peru, Illinois|Peru]]; as it intersects [[Interstate 80 in Illinois|I-80]] and [[U.S. Route 6 in Illinois|US&nbsp;6]], it makes its southernmost connections with the Chicago region. North of I-80, the wind turbines of the [[Mendota Hills Wind Farm]] (the first commercial wind farm in Illinois) can be seen from milepost&nbsp;72 at [[Mendota, Illinois|Mendota]] north to near [[Paw Paw, Illinois|Paw Paw]]. As I-39 continues northward, I-39 also intersects [[U.S. Route 52 in Illinois|US&nbsp;52]] and [[U.S. Route 30 in Illinois|US&nbsp;30]].

In [[Ogle County, Illinois|Ogle County]], I-39 intersects with [[Interstate 88 (Illinois)|I-88]] ([[Chicago–Kansas City Expressway|IL&nbsp;110]]), connecting I-39 to both Chicago and the Quad Cities regions. As it intersects [[Illinois Route 38|IL&nbsp;38]], [[Illinois Route 64|IL&nbsp;64]], and [[Illinois Route 72|IL&nbsp;72]], I-39 connects with the DeKalb–Sycamore region and far west suburbs of the Chicago area.

As I-39 crosses into Winnebago County, the Baxter Road exit (exit&nbsp;115) is the final exit before I-39 joins the [[U.S. Route 20 in Illinois|US&nbsp;20]] freeway bypass in Rockford. Approximately a mile east of the Alpine Road/US&nbsp;20 interchange, I-39 joins US&nbsp;20, moving from nearly entirely farmland to medium-density populated areas.

After heading northeast for approximately {{convert|4|mi|km|spell=in}}, US&nbsp;20 splits from I-39/US&nbsp;51; a mile northward, I-39/US&nbsp;51 runs concurrently with I-90 ([[Interstate 90 in Illinois#Jane Addams Memorial Tollway|Jane Addams Memorial Tollway]]). Though signed as I-39/I-90, the concurrency follows the mileposts of I-90. Though I-39 itself is not tolled, the [[Illinois Tollway]] collects tolls on the I-90 portion, including two ramp interchanges and an open-road toll plaza between Rockton and South Beloit.

At exit&nbsp;1 ([[Illinois Route 75|IL&nbsp;75]]) in [[South Beloit, Illinois|South Beloit]], US&nbsp;51 splits from I-39 to join IL&nbsp;75; {{convert|2|mi|km|spell=in}} westward, it continues the route of IL&nbsp;251 into Wisconsin. For all but one mile that I-39 is in Illinois, it runs concurrently with US&nbsp;51.{{clear left}}