When Henry had established his fort at the confluence of the Yellowstone and the Missouri in 1822, Smith was sent back to St. Louis to advise General Ashley of the needs of Henry and his men for the following year. Smith then accompanied Ashley west in the spring of 1823, and as mentioned previously, was sent ahead to enlist Henry’s aid when Ashley ran into trouble with the Arikaras. He again returned with the General to St. Louis, and in February 1824, Ashley sent him out again with a party which traveled overland by pack train. On this occasion Smith and his party made the first crossing, east to west, of the famous South Pass at the head of the Sweetwater River, the pass which was to become the crossing of the Great Divide on the Oregon Trail. This pass had been used by the Astorians, traveling in the opposite direction, in 1812. (General Dodge’s memorial, crediting discovery of the pass to Bridger in 1827, was thus in error, although various routes were being “discovered” and “re-discovered” at intervals by individuals who had no knowledge that others had preceded them.) A new era in fur trade history was opened when Smith’s party found the rich beaver fields at the head of Green River. As Smith and his contingent moved north from the Green, they entered Jackson Hole by way of the Hoback, passed through the valley, and crossed north of the Tetons by way of Conant Pass into Pierre’s Hole (the Teton Basin.) Thus Smith preceded Bridger into Jackson Hole by a year. Although Smith became possibly the greatest of the trapper-explorers, at least with relation to the wide territory covered in the course of his journeys, he did not return to Jackson Hole. He was killed by Comanches only 7 years later on the Santa Fe Trail. Crossing desert country with a wagon train, Smith was scouting ahead for water when he was slain. His remains were never found, the story of his death came to light when Mexican traders, who dealt with the Comanches, brought his pistols and rifle to Santa Fe. William “Bill” Sublette and David E. Jackson became Smith’s partners in the fur trade when they bought Ashley’s interests in the business at the rendezvous near the Great Salt Lake in 1826. Both of these men had been among those who made up Ashley’s 1822 expedition, Sublette at that time was 24 years of age, a Kentuckian whose family moved to Missouri in 1817. Jackson has remained throughout the years an enigma, practically nothing is known of him before his advent into the fur trade, or following his activity as a mountain man.