Demand for beaver pelts in the early 1800s drove exploration and eventual settlement of the American West, and South Pass became significant as part of a major thoroughfare through the Rockies during the fur trade. White men first crossed South Pass in 1812, when the Astorians, a small party of American Fur Company trappers led by Robert Stuart, traveled east through it with dispatches for company owner John Jacob Astor. Although Stuart recorded South Pass in his diary and news of his journey appeared in a Missouri newspaper, another decade passed before white men rediscovered it. In the winter of 1823-24, Jedidiah Smith and other mountain men working for William Ashley found the Wind River Range a barrier to the beaver-rich Green River Valley farther west, and after failing to pass through Union Pass to the north, they reached the Green River by crossing the southern end of the range at this gradual incline. In 1825, as he traveled west with supplies, Ashley began the Rendezvous, an annual event that continued until about 1840, when demand for beaver declined.