The Delaware Lackawanna & Western Railroad took delivery of five 4-8-2s (road numbers 1401 through 1405) from the American Locomotive Company in 1924. These "Mountains" had 69" drivers and were not particularly well suited for passenger service and were relegated to secondary trains. They were sold to the Atlantic Coast Line Railroad during World War II.

Five more 4-8-2s (road numbers 1450 through 1454) came from ALCO in 1925. These locomotives had three 25" x 28" cylinders, 73" drivers, a 200 psi boiler pressure and exerted 61,100 lbs of tractive effort. By 1931 DL&W had rebuilt them as two cylinder locomotives.

In 1926 and 1927, the DL&W received thirty more "Mountains" (road numbers 2201 through 2235) from ALCO to be used as pushers and to drag coal trains. These locomotives had three cylinders, two 25 x 32 outside cylinders driving the third drivers and one 25 x 28 inside cylinder driving a crank on the second axle. With 73" drivers and a boiler pressure of 200 psi they exerted 77,600 lbs of tractive effort.

By 1950, all of the DL&W "Mountains" were gone and there are no surviving examples.