The St. Louis-San Francisco Railroad converted 10 of its older 4-6-2 Pacifics into 4-6-4 Hudsons. These Pacifics were built by the Baldwin Locomotive Works in 1917. Five of the conversions were completed in 1937, two more in 1940 and the last three in 1941. These 10 new oil burners were given road numbers 1060 through 1069.