Joseph Reddeford Walker was one of the most prominent of the explorers, and charted many new paths through the West, which often were then utilized by emigrants crossing to settle in Western towns and communities. In 1833, his exploring party discovered a route along the Humboldt River across present-day Nevada, ascending the Sierra Nevada following the Carson River and descending via Stanislaus River drainages to Monterey. His return route across the southern Sierra was via Walker Pass, named after Walker by John Charles Fremont. The approach of the Sierra via the Carson River route later became known as the California Trail, the primary route for the emigrants to the gold fields during the California gold rush.