Bridger and Vasquez acted on the indications. In the valley of Black’s Fork, Uinta County, the southwestern corner of Wyoming, a day’s ride from the sites of many rendezvous, on the natural route from the Sandy, a route which they foresaw would prove a better one for wagons coming out of South Pass than the routes by which they had taken pack trains westward – in the valley of Black’s Fork they built a new post, Fort Bridger. They established it not as a headquarters for beaver hunters and not as a depot for the trade with Indians, but as a supply station for emigrant trains. It was built (apparently in the summer of 1842) in time to serve the first really big wave, the one which the texts call the Great Migration, the emigration of 1843, and the history of the West through the next fifteen years could be intelligently written along radii that center here. With the establishment of Fort Bridger, General Chittenden is content to say, the era of the mountain man ended.