Yosemite Mountain Sugar Pine Railroad

The Yosemite Mountain Sugar Pine Railroad (YMSPRR) is a heritage 3 ft (914 mm) narrow gauge railway near Fish Camp, California, in the Sierra National Forest near the southern entrance to Yosemite National Park. The railroad operates three steam locomotives. Rudy Stauffer founded the railroad in 1961 along part of the former route of the Madera Sugar Pine Lumber Company.

Operations began with the acquisition of three-truck Shay locomotive No. 10 from the West Side Lumber Company railway in Tuolumne, California. Built in 1928, No. 10 has been described as the largest narrow-gauge Shay locomotive built and was among the last constructed. In 1986, the railroad acquired Shay No. 15, another former West Side Lumber Company locomotive, from the West Side and Cherry Valley Railroad in Tuolumne. In 2026, the railroad acquired No. 12, originally built for the Swayne Lumber Company and later operated by the West Side Lumber Company, from the Colorado Railroad Museum.

The steam locomotives operate during the summer season, while the railroad's "Jenny" railcars are typically used during the off-season. Passengers ride in either open-air or covered passenger cars.