The Applegate-Lassen Trail is a 130 mile section of the larger Applegate and Lassen trails running through Pershing, Humboldt, and Washoe Counties, beginning where it parts from the California Trail at the Humboldt River and the northern end of Rye Patch Reservoir and continuing to its exit west of Vya, Nevada. Together with the Oregon and California trails, these routes formed the longest, most significant, and most heavily traveled paths of western migration in American history. On June 29, 1846, Jesse and Lindsay Applegate left Willamette, Oregon, heading southeast in search of a less treacherous route through the harsh Nevada landscape to the Oregon Territory, and on July 21, 1846, they reached the north end of Rye Patch Reservoir, where the junction with the California Trail is still visible. The area later served as a place to recruit and water emigrants' stock, and pioneers also left messages for those following at a functional post office at the junction. Later that year, Peter Lassen, seeking to bring emigrants to his ranch, guided a wagon train of 10 to 12 wagons to Goose Lake, Oregon, then turned south and created the Lassen Trail. Along the Applegate-Lassen Trail are 19 historic sites linked to the overland migration of the 1800s to Oregon and California, as well as a number of springs including Antelope (Willow) Spring, Rabbithole Spring, Black Rock Spring, Double Hot Springs, Stevens Spring, Emigrant Spring, and Fortynine Spring. The remaining traces of the Mud Lake Crossing form the longest unbroken stretch left of this historic pathway to the West, extending 20 miles.