Mile 1075: South Pass

“The Sweetwater Valley took the emigrants smoothly uphill 1oo miles to the Continental Divide at South Pass. This fortuitous gap in the Rockies exists because of geologic happenstance. A Wind River-sized mountain range—the Sweetwater Range—once filled the east-west gap where the Sweetwater Valley is now. Several million years ago, it foundered to form the valley, thus opening the way west to South Pass. The Sweetwater Hills represent the exposed ridgeline of this buried range. These granite hills include two of the most famous landmarks on the Oregon-California Trail: Independence Rock and Devils Gate.”