| No. | Class | F.M. Whyte | Gauge | Railroad Line | Location | Status | Builder Info | Notes |
|---|---|---|---|---|---|---|---|---|
| 3977 | 46644 | 4-6-6-4 | 4'-8½" | UP | Cody Park, North Platte, NE | display | Alco (Schenectady) #70160, 1943 | One of only two surviving UP Challenger locomotives, the other one being UP 3985. Displayed with UP Centennial 6922. |
| 3985 | 46644 | 4-6-6-4 | 4'-8½" | UP | Railroading Heritage of Midwestern America, Silvis, IL | restoration | Alco (Schenectady) #70174, 1943 | Restored to operation in Apr 1981. Masqueraded as UP 3967 in 1993 and 2003. Taken out of service in Oct 2010. Retired from the UP's steam excursion program in Jan 2020. The tender is being used behind UP 4014. Donated to RRHMA, Silvis, IL on Apr 28, 2022. |