In the 1820s and 1830s, what’s now western Wyoming was at the center of the fur trade of the northern Rocky Mountains. Indians, trappers and their suppliers met each summer at a big trade fair called rendezvous, where trappers exchanged their season’s beaver pelts for hardware, whiskey and supplies. By 1840, demand for beaver had disappeared and the species had been nearly rubbed out. But the rendezvous supply routes were already becoming the trails that would bind the nation together.