To test the 4-8-4 wheel arrangement on its railroad, the Chicago, Rock Island & Pacific Railroad bought one Class R-67a 4-8-4 (road number 5000) from the American Locomotive Company in 1929. The locomotive performed so well that CRI&P bought 24 more (Class R-67b) before the year ended (road numbers 5001 through 5024). In 1930, 40 more (road numbers 5025 through 5064) were purchased from ALCO.

These 65 locomotives had 69" drivers, 26 x 32 cylinders, a boiler pressure of 250 psi, weighed about 437,000 lbs and had a tractive effort of 66,620 pounds. Although designed for freight trains they were also used in passenger service and some were rebuilt with 73" drivers to provide more speed when used on passenger trains.

In 1944, CRI&P took delivery of ten more Northerns (road numbers 5100 through 5109) and in 1946, ten more (road numbers 5110 through 5119). All twenty of these Class R67-b Northerns came from ALCO. The first ten were oil burners and the last ten were delivered as coal burners. These 20 locomotives had 74" drivers, 26 x 32 cylinders, a boiler pressure of 270 psi, a weight of 474,500 lbs and a tractive effort of 67,088 pounds.

The CRI&P had the largest fleet (85) of these locomotives in the United States and was second to the Canadian National Railroad in North America and third to the USSR in the world. No CRI&P Northerns were saved.