At 9:15 am., Tuesday, August 27, 1957, at the Atchison, Topeka & Santa Fe Railway engine terminal at Belen, N. Mex., 4-8-4 No. 3780 was called to help a four-unit EMD F7 diesel on an eastbound freight train up the 1.25 per cent grade through Abo Canyon to Mountainair, 41 miles away. An hour earlier, 2-10-4 No. 5021 had been called to help an earlier freight. No. 5021 returned at 1:15 p.m. At 2:15 p.m., Engineer G. 1. Riley and restricting Fireman M. E. Key brought the 1941 Baldwin 4-8-4 back to Belen, ending the usage of steam power in revenue service on the Santa Fe System 88 years, 4 months, and 1 day after it began in Kansas.

This last trip of No. 3780 also ended over 30 years of Santa Fe operation of 4-8-4's. The pioneer engine of this type, No. 3751, had been delivered by Baldwin Locomotive Works in May 1927. During three decades, 65 4-8-4's set records for speed, dependability, and long-distance engine runs. The 51 engines of the later 3765, 3776, and 2900 classes can be ranked at or near the top of 4-8-4's built for North American service.