English: Front view of the Grand Trunk Western 4070 Light Mikado locomotive undergoing restoration at the former B&O Railroad roundhouse in Cleveland, Ohio, in the United States. The roundhouse has been owned by the Midwest Railway Preservation Society sinc 1954.

This is an M-3 model Light Mikado locomotive designed and built under the auspices of the United States Railroad Administration, the nationalized railroad administration in the United States during World War I. A total of 625 locomotives were built, 25 for the Grand Trunk Western Railroad. This locomotive was built by the American Locomotive Company (ALCO) in 1918.

It bears the name "Mikado" because that is the name given to locomotives with a 2-8-2 wheel arrangement. Mikados had a single truck in the for (with two unpowered wheels on one axle), eight powered and coupled wheels on four axles, and a trailing truck (with two unpowered wheels on one axle). A coal-fired steam locomotive, its boiler could generate 200 psi (1.38 MPa), and 54,724 lbf (243.42 kN) of tractive effort.

This locomotive was originally numbered 3734, and used on the GTW in Michigan as a passenger and freight locomotive. Her number was changed to 4070 in 1957. It was retired in 1960, and leased by the Midwest Railway Preservation Society. The lease expired in 1966, and the locomotive was sold to various excursion train companies in Illinois, Indiana, Pennsylvania, and Ohio. The MRPS bought the locomotive in 1971. It was leased for excursion work in Ohio until 1975, when it was leased to the Cuyahoga Valley Scenic Railroad.

In 1984, this locomotive was filmed for the movie "The Natural". Needing extensive repair, the locomotive was retired again in 1990. It began restoration in 2011. Restoration is proceeding very slowly due to lack of available funds.