Weber became acquainted with
William Henry Ashley and
Andrew Henry who conducted the beaver trade in the drainage basin of the Upper
Missouri River. He joined a
Rocky Mountain Fur Company expedition which departed
St. Louis, Missouri in the spring of 1822. Other trappers in this group included
Jim Bridger, David Jackson,
Jedediah Smith,
Thomas Fitzpatrick,
Hugh Glass,
James Clyman, Daniel T. Potts, and
Milton Sublette. This was the first party of American trappers to cross the
continental divide. Upon reaching the mouth of the
Yellowstone River, the company divided into two independent brigades, with Weber serving in a leadership position. During the summer of 1824, Weber's brigade crossed
South Pass and the
Green River Valley and descended into the
Bear River region in time for a fall hunt. As winter approached, the company journeyed to
Bear Lake, then to the Bear River's northern bend and finally south into the
Cache Valley. The brigade spent the winter of 1824–25 on Cub Creek near present-day
Cove, Utah. While in Cache Valley, the group discussed the possible course and ultimate outlet of the Bear River. According to his own account, the young Bridger was selected to settle the question by floating down the river. For many years Bridger was credited with the discovery of the
Great Salt Lake. More recent evidence suggests that Canadian-American
Etienne Provost and his trapping party, working out of
Taos in Mexican territory, visited the southern edge of the inland sea earlier in the same winter. The following spring, Weber's brigade traveled throughout extreme southeastern Idaho and northern Utah. A portion of the brigade, under the leadership of Johnson Gardner, confronted
Peter Skene Ogden, the leader of
Hudson's Bay Company (HBC) Snake Country Expedition near present-day
Mountain Green, Utah. Gardner insisted that they were in United States territory. Ogden countered that the area in contention was under joint occupation. During the incident Gardner was able to lure a number of men, many of them Canadian
Iroquois, away from their British employer by offering higher prices for their furs. The reduction in force led Ogden to retrace his steps back to the HBC "Flathead House" near
Flathead Lake in modern Montana. That summer, Weber and his brigade were at the first
rendezvous held in
Sweetwater County, Wyoming, near present
McKinnon, just north of the Utah border. Weber's remaining mountain years are less well documented; however, he spent the winter of 1825–26 in the Salt Lake Valley, after Ashley's men were forced by severe winter weather to move their winter quarters from Cache Valley. It appears that Utah's Weber River was
christened during this winter camp. This name gave rise to the present names of Utah's
Weber Canyon,
Weber County and
Weber State University. Weber attended the rendezvous of 1826 in Cache Valley and left the fur trade, and the
West, shortly thereafter. However, some accounts confuse John Henry Weber with a trapper named John Weber, who was killed by Indians in the winter of 1828–29. ==Later years and death==