Santa Fe 3751 hauled passenger trains toward the End of the Steam Era in the US in 1957 with the rest of its 4-8-4 "brothers" and remained preserved on static display until 1989, when the San Bernardino Railroad Historical Society decided to rebuild and restore 3751 after being in such poor condition and suffering lack of maintenance and vandalism from the park it was originally displayed in. (Similar to SP 4449's dilemma.)
In 1991, 3751 returned to the rails with preservationists efforts as well as with the help of the Santa Fe. It's first excursion was pulling a mixed train of passenger and freight cars, which served as its "trial run" (or test run) to demonstrate or prove 3751's operating capabilities. Yet because of "his" age, 3751 stalled towards the end of its run, thus the need for having diesel locomotives assist the aging steam locomotive was actually necessary. Thus, a week after its first test run, 3751 was hauling its very first passenger excursion train; the California Limited; between Los Angeles and Bakersfield and back for the first time in many years with the help of 2 Santa Fe "Warbonnet" painted FP45's repainted and renumbered for excursion service with 3751.
Today, when on long distance excursion, 3751 is typically seen with one or more Amtrak P42DC type locomotives following. The diesel assitance is necessary for three reasons: protection, power, and dynamic braking. Protection against 3751 failing en route and tying up a mainline, providing HEP power for any following passenger cars, and utilizing the diesel locomotive's dynamic braking when going down steep grades.
In August 2002, the locomotive went to Williams, AZ, for the annual NRHS convention.
In September 2008, the locomotive was hauling the Private Varnishs Special from Los Angeles to San Diego and back.
3751 also doubleheaded with GCRY (Grand Canyon Railway) 4960 to pull a special charter train to the Grand Canyon and back.
In May 2011, and 2009 3751 was invited by Amtrak to display at Los Angeles Union Station for National Train Day.
In June 2004, 3751 was invited to participate in the rededication of the San Bernardino Santa Fe Depot following an extensive restoration effort.
In 1986, 3751 was moved from its display to California Steel Industries, where it was restored at a cost of $1.5 million and in 1991, operated for the first time in 38 years. Since then, it has done countless excursions and special trips and gone to many events.
In April 1995, Santa Fe 3751's original Santa Fe 5-Chime Freight whistle was replaced with it's new Santa Fe 6-Chime Passenger whistle, just 5 months before the BNSF merger.
In May 2001, 3751 was displayed at Fullerton Railroad Days in Fullerton, CA.
In May 2007, 3751 was invited to participate in the annual Fullerton Railroad Days in Orange County. This locomotive was also to be put on display in Fullerton and was the lead locomotive for the special movement along the BNSF's San Bernardino Subdivision.
Later in August 2002, Santa Fe #3751 and Grand Canyon #4960 triple headed with Grand Canyon #18.
In 1992, 3751 was hauling the Employee Appreciation Special traveling from Los Angeles to Chicago and back With a help from 3 to 2 of Santa Fe "Warbonnet" painted GE C40-8.
In 2012, 3751 went back to Williams, Az, for the second annual NRHS convention.
This locomotive only operates in occasional excursion service along side with SP 4449.