Between the 1840’s and the 1880’s, many emigrant pioneers passed through this opening in Emigrant Ridge as they traveled the Oregon-Mormon Trail by oxen-drawn wagons, on horseback, or on foot. The trail generally followed the North Platte River from the Scottsbluff, Nebraska area to crossings near Fort Caspar, which was active between 1862 and 1867. Near Fort Caspar, the trail left the North Platte River and meandered overland toward Willow Springs, Ryan (Prospect) Hill, the Sweetwater River drainage, Independence Rock, South Pass, and beyond to Utah, Oregon, and California. From this point, emigrants had a sweeping view to the west, the scene of their next week’s journey. Emigrant Gap marked their departure from the North Platte River valley and the beginning of the ascent into the Rocky Mountains, and the trail crossed the Continental Divide at South Pass.