In 1830, Walker was driving horses to
Fort Gibson in Oklahoma, where he met
Benjamin Bonneville. Walker wanted to explore the
American frontier, and Bonneville offered him an opportunity to join him in his expeditions. In 1832, Walker left from Fort Osage with Bonneville and 110 other men, traveling to the
Green River in
Wyoming. In 1833, Bonneville sent Walker in command of a party of men, including Old Bill Williams and Zenas Leonard, from the Green River to explore the
Great Salt Lake and to find an overland route to
California. They left on July 27 and eventually discovered a route along the
Humboldt River across present-day
Nevada. They followed it to the
Humboldt Sink, then made their way to present day
Genoa, Nevada at the base of the
Sierra Nevada. They began their ascent of the Sierra by traveling up the west fork of the
Carson River to
Hawkins Peak. At that point, they began wandering, trying to find a path to a dividing ridge and down the western slope. They finally made their way to the headwaters of the
Stanislaus River and descended on the ridgeline north of the river canyon. They eventually made it to the river itself, then followed it down to the
Central Valley of California. According to Walker's gravestone, he camped in
Yosemite on Nov. 13 1833, though this is disputed. The approach to the Sierra via the Humboldt River route later became known as the
California Trail, the primary route for the emigrants to the
gold fields during the
California gold rush. On February 14, 1834, Walker and his party of fifty-two men left on their return trip from California, crossing back over the Sierra Nevada through one of the southern passes. The group made it to
Owens Valley on May 1, 1834, and traveled up it but became impatient to turn east. They crossed out of the valley on May 10 but soon became alarmed by the lack of water. They went back west to the base of the Sierra and traveled north to the Humboldt Sink, then they traveled back to the Rocky Mountains the way they had come the previous summer. At some point in the ensuing years, Walker took a
Shoshone wife. ==Emigrant leader==