The Sumpter Valley Railway was a narrow gauge railroad, which began in Baker City, Oregon in 1890. It followed the Powder River through Bowen Valley to Salisbury, just 9 miles south of Baker City and continued on the McEwen. In the 1892, a major gold strike was found, near the town of Sumpter and a boom began. The railway was extended the six miles to Sumpter by 1896. When the railroad came to Sumpter the population was 200 people, with it came a surge in population and by 1897 the town grew to about 9,000 people.

In 1900, the track was laid over Larch summit, an altitude of 5094 feet, and down the west side of Huckleberry Mountain. By 1901, the tracks reached Whitney, an Oregon Lumber Company town. Tracks were constructed from Whitney in all directions. Some spur lines went 14 miles into the woods. It was not long before a depot was built.

During 1903, the tracks were extended across the Whitney Valley, over the North Fork of the Burnt River, and up the pass of the Greenhorn Mountains to the Tipton summit, at 5127 feet. The rail reached Tipton in 1904. A station was built in Tipton and a wye constructed to turn the helper engines. From Tipton the railway entered Grant County, traveling down the mountain to what later became White Pine. Soon the rails were reaching down the mountainside 8 miles from White Pine, arriving at the stage stop of Austin, in 1905. In 1909 the track crews began constructing the final segment of the railway 21 miles south of Austin. By June 1910, the tracks descended to the John Day Valley, crossed the John Day River and were completed to Prairie City. The railway was now 80.1 miles from Baker City.

By July 1937, passenger service along the line was discontinued and the last freight train steamed into South Baker on June 12, 1947. Shortly thereafter the rails were pulled, the lines completely dismantled, and the land on which the tracks were laid was sold or abandoned. The Oregon Lumber Company operated a sawmill in South Baker until the middle 1950's, when the company was sold to Edward Hines Lumber Company. The SVR chugged back and forth in the lumberyards until 1961.

In 1970 a group of Baker County residents got together and formed a preservation society to acquire as much of the remaining equipment of the original Sumpter Valley Railway right of way as possible. They hoped to restore a portion of the original line to operation. In 1971 the group was able to purchase 2-truck, wood burning Heisler No. 3 from Boise Cascade. The locomotive had survived all these years in a shed in Cascade ID serving as a backup boiler to a lumber mill until 1969. The Union Pacific donated rails and ties and a couple of flat cars were obtained from the D&RGW.

The Sumpter Valley Railway purchased two narrow gauge “Mikados” from the American Locomotive Company in the 1920. They were built to Sumpter Valley Railway specifications and were the first locomotives the SVRY bought new from the factory after decades of using second and third hand locomotives. These locomotives weighed 224,000 pounds and had 44” drivers, 19” x 20” cylinders, a 170 psi boiler pressure and exerted 23,700 pounds of tractive effort. The SVRY also had three Baldwin built Mikados, numbers 16, 17 & 18.

After 20 years, when the SVRY bought the two famous Unitah “Mallets”, the “Mikados” were retired and their tenders put behind the “Mallets”. In 1942, when the US Army took control of the White Pass and Yukon during the war to aid in the construction of the Alaska Highway, they bought the two “Mikados”, less the tenders, and shipped them to Alaska. There they became numbers 80 and 81 and saw heavy service until being retired again.

The “Mallets”, with the “Mikado's” tenders, were sold to Guatemala, where they were run until they fell apart and were scrapped - except for the tenders. The Sumpter Valley Railroad Restoration in 1971 got the two “Mikados” back from Alaska, and the tenders back from Guatemala. “Mikado” #19 has been fully restored and is now in operation summers on the Sumpter Valley Railroad. “Mikado” #20 is unrestored and on display there, however, a fund has been set up for its restoration. The railway operates from Memorial Day through the last weekend in September.