Editing National Trails System (section)

== National Geologic Trail ==
The first national geologic trail was established by the [[Omnibus Public Land Management Act of 2009]], though it did not amend the National Trails System Act to create an official category.<ref>{{Cite web |title=[USC02] 16 USC 1244: National scenic and national historic trails |url=https://uscode.house.gov/view.xhtml?req=%22National+Geologic+Trail%22&f=treesort&fq=true&num=0&hl=true&edition=prelim&granuleId=USC-prelim-title16-section1244 |access-date=2021-05-06 |publisher=US House of Representatives}}</ref>

{| class="wikitable"
|+National Geologic Trail
! scope="col" | Name 
! scope="col" | Image
! scope="col" | States on route
! scope="col" | Agency
! scope="col" | Year {{abbr|est.|established}}
! scope="col" | Length
! scope="col" | Description
|-
! scope="row" |[[Ice Age Floods National Geologic Trail|Ice Age Floods]]
|[[File:Dry Falls (Washington).jpg|200x200px|alt=Plateau with steep walls of a former waterfall above a river]]
|Washington, Oregon, Idaho, Montana
|NPS
| 2009
|{{cvt|3400|mi|km|-1}}
|From around 18,000 to 15,000 years ago, the [[Lake Missoula|glacial Lake Missoula]] breached its ice dams 40 to 100 times, each time releasing the cataclysmic [[Missoula floods]] that carved [[Coulee|coulees]], lakes, cliffs, waterfalls, and [[giant current ripples]] along their path. They created the [[Channeled Scablands]] that form much of eastern Washington's landscape of irregular buttes and basins and the [[Columbia River Gorge]] past the [[Wallula Gap]]. An unmarked tour route connects a network of state parks and other featured sites formed in these erosive floods such as [[Steamboat Rock State Park]], [[Dry Falls]] (pictured), [[Palouse Falls]], and the [[Grand Coulee]].<ref>{{Cite web |title=Ice Age Floods National Geologic Trail |url=http://www.nps.gov/iafl/ |access-date=April 11, 2021 |publisher=National Park Service}}</ref><ref>{{Cite web |date=June 2016 |title=Ice Age Floods National Geologic Trail Long-Range Interpretive Plan |url=http://www.gigaflood.com/IAFL%20LRIP_ADOBE.LowRes.pdf |publisher=National Park Service}}</ref>
|}