Devil’s Gate on the Sweetwater River became an important landmark for emigrants on the Oregon/California/Mormon trails. Trader Charles Lajeunesse ran a post there in the 1850s, not long before a Mormon handcart company sought shelter from a blizzard at nearby Matins Cove. Later, the famous Sun Ranch was headquartered there for 125 years.
The basin of the North Platte River takes up the southeastern quarter of Wyoming, plus a finger of land along the tributary Sweetwater River in the center of the state. The courses of the North Platte and Sweetwater determined early fur-trade and emigrant routes. Since that time, the basin’s water and other resources have continued to draw industry, stock raising, dams and irrigation—and people.