| No. | Class | F.M. Whyte | Gauge | Railroad Line | Location | Status | Builder Info | Notes |
|---|---|---|---|---|---|---|---|---|
| 4014 | 48841 | 4-8-8-4 | 4'-8½" | UP | UP engine house, Cheyenne, WY | operational | Alco (Schenectady) #69585, 11/1941 | From Pomona, CA. Reacquired by the Union Pacific in July 2013. Restored to operation on May 1, 2019. Converted to burn oil. Temporarily uses the tender of UP 3985. Became the first-ever steam locomotive to be equipped with Positive Train Control. |
| 4004 | 48841 | 4-8-8-4 | 4'-8½" | UP | US 30, Holliday Park, Cheyenne, WY | display | Alco (Schenectady) #69575, 09/1941 | Cosmetically restored in 2018. |
| 4005 | 48841 | 4-8-8-4 | 4'-8½" | UP | Forney Transportation Museum, Denver, CO | display | Alco (Schenectady) #69576, 10/1941 | First UP Big Boy to be converted to burn oil before UP 4014. Converted back to burn coal in March 1948. Only UP Big Boy to be involved in an accident. |
| 4018 | 48841 | 4-8-8-4 | 4'-8½" | UP | Museum of the American Railroad, Frisco, TX | display | Alco (Schenectady) #69589, 01/1942 | Displayed with UP Centennial 6913. |
| 4017 | 48841 | 4-8-8-4 | 4'-8½" | UP | National Railroad Museum, Green Bay, WI | display | Alco (Schenectady) #69588, 01/1942 | Displayed with PPR GG1 4890. |
| 4023 | 48842 | 4-8-8-4 | 4'-8½" | UP | Lauritzen Gardens, Omaha, NE | display | Alco (Schenectady) #72780, 11/1944 | Displayed with UP Centennial 6900. Repainted in 2025. |
| 4012 | 48841 | 4-8-8-4 | 4'-8½" | UP | Steamtown National Historic Site, Scranton, PA | display | Alco (Schenectady) #69583, 11/1941 | Underwent a cosmetic restoration between 2019 and 2021. Displayed on a curved track in front near the parking lot. |
| 4006 | 48841 | 4-8-8-4 | 4'-8½" | UP | Museum of Transportation, St. Louis, MO | display | Alco (Schenectady) #69577, 10/1941 | Displayed with UP Centennial 6944. Cosmetic restoration completed in 2023. |