The Climax was the second most popular of the geared engines designed for use on logging railroads, after the Shays. Climax Manufacturing Company of Corry, Pennsylvania, built an inexpensive "Type A" that looked like a boiler and engine on a flat car, but larger locomotives had inclined cylinders that drove a cross shaft geared to a flexible shaft beneath the machine, which was in turn geared to each axle. Climax had a reputation for great flexibility on rough track.

As early as 1891, Climaxes were built for West Virginia. Several companies, including W. M. Ritter Lumber Company, bought as many as six small locomotives each for use on narrow gauge track. When Climax Manufacturing went out of business in 1928, more than 140 Climax engines had been used in West Virginia. Some companies that preferred Climax were Sewell Lumber at Landisburg (five narrow-gauge engines), Elk River Coal & Lumber at Swandale (four, one of which was the last Climax in service in the United States), and Moore-Keppel at Ellamore (six).

Climax No. 9 has been restored and is in use at Cass Scenic Railroad, and another is in service on the Durbin and Greenbrier Valley, both in Pocahontas County. Of a mere dozen Climaxes left in America today, five were used in West Virginia.