High Quality Content by WIKIPEDIA articles! The Yosemite Mountain Sugar Pine Railroad (YMSPRR) is a historic 3 ft (914 mm) narrow gauge railway with two operating steam train locomotives located near Fish Camp, California, in the Sierra National Forest near the southern entrance to Yosemite National Park. Rudy Stauffer organized the YMSPRR in 1961, utilizing historic railroad track, rolling stock and locomotives to construct a tourist line along the historic route of the Madera Sugar Pine Lumber Company.