Geologic History

Fish Creek Canyon is a glacial valley that rests in the Routt National Forest territory of the Park Range in Steamboat Springs, CO. The modern streams in the valley, the Fish Creek and the North Fork Fish Creek flow from Long Lake, a glacial lake located 5 miles from the start of the USFS trailhead. The glacial sediment formed from the erosion updip and deposition downdip gives the creeks a foundation of hard rock material. The sedimentary deposits surround much of the basin and are tell tale signs of a glacial deposit. The waterfall, an iconic tourist destination is categorized as a “hanging valley” that contributed to the main glacial valley.

The U-Shaped valley differs from a river carved V-Shaped valley. The glacial scouring of the Fish Creek valley left a large trail of geologic material, some small boulders line the creek bed as modern day evidence of the valley formation. The glacial formation was not limited to the Fish Creek Basin as much of the Yampa Valley’s water sources come from previous glacier valleys.

The Fish Creek Glacial Valley can be seen above with the Soda Creek, Mad Creek, and South Elk Glacial Valleys; all which remain a water source for recreation and ranching. The Fish Creek valley is unique because the oxidized groundwater led to a unique phenomena in Routt County. The surface rocks, left behind from the glaciation period, leached uranium into fresh water aquifers. There, the uranium reduced to precipitate uraninite, considered the primary ore mineral of uranium.

The history of uranium will be covered in the next blog post!