The California Trail was a major overland immigrant trail of about miles ( km) across the western half of the North American continent from Missouri River towns to what is now the state of California. It was used primarily from 1841 to 1869. It followed the same corridor of trails, following different river valleys, as the Oregon Trail and the Mormon Trail till it turned off in Idaho, Wyoming or Utah to follow trails leading to the Humboldt River valley. Most of the trail across the Great Basin in Nevada followed the Humboldt River valley to obtain the water, grass and 'wood' needed by all travelers. Once in western Nevada and eastern California the pioneers worked out several paths over the rugged Sierra Nevada mountains into the gold fields, settlements and cities of western California.