[10] 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.

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.

[16] In 1840 Walker and a band of followers made the first known north to south crossing of the eastern Great Basin by Americans.

In August, at Black's Fork of the Green River, the party stopped to rest the animals and hunt, trying to stock dried meat for the trail.

They were marginally successful, and being able to only acquire four head of cattle at Ft. Hall, Walker and Chiles decided to split the party in order to make best use of the remaining provisions.

[h] The Chiles group was unable to obtain provisions at Fort Boise and circumvented the Sierra Nevada far to the north, rather than crossing at the Truckee River.

About the journey Gilbert states, "The overland caravan had done no true exploring but had laid down 500 miles of what was to become the California Trail".

[17] The trail segment referred to appears to extend from Fort Hall (Idaho) to the Truckee River (Nevada and California).

In 1845, by prearrangement, Walker, with his wife and retainers, joined Frémont's third government expedition at White River (eastern Utah) bound for California and Oregon.

The party again divided, with Walker taking the main body to the current location of Lake Isabella in December while Frémont and a small group crossed the Sierra Nevada in the vicinity of Truckee River, eventually reaching Sutter's Fort (California).

The two parties missed their planned rendezvous along the Kings River in the San Joaquin Valley but were reunited in February 1846.

Several different places are named for Walker, including: This article incorporates public domain material from websites or documents of the National Park Service.