The first American emigrants who attempted a wagon crossing from Missouri to California; led by Captain John Bartleson. In May 1841, the Bartleson Party assembled at Sapling Grove, near Westport, Missouri under the organization of the twenty-one-year-old John Bidwell. At Fort Hall, in present day Caribou County, Idaho, a 19th-century military and trading outpost about half of the original party changed their plans and decided to take the easier road into Oregon. The remainder of the Bartleson-Bidwell party split off from the trappers' trail to Oregon and headed west along the north shore of the Great Salt Lake, where they were forced to abandon their wagons in the desert west of the lake.
Accompanied by their surviving animals, they eventually found the "Mary's River" (later the Humboldt River) and followed it to its sink (near present-day Lovelock). Crossing the desert to the south, they reached the Walker River, which they ascended over the Sierra Nevadas in the same region crossed by Jedediah Smith in 1828.