Craig Mountain Lumber Company No. 3 is crossing a trestle near Rockaway Beach, Oregon.

No. 3 is a two-truck Heisler built by the Heisler Locomotive Works in 1917 for the Craig Mountain Lumber Co. These "off-road vehicles" of railroading could handle steep grades, temporary, un-ballasted track and even ford a stream. In the 1890s, an inventor named Charles Heisler created the locomotive that bore his name and was the last of the major types of geared steam power.