Earlier this week, Utah Railway No. 5004 — an MK50-3 — arrived at Ogden Union Station on a loan from the Promontory Chapter of the National Railway Historical Society which just recently bought the 31-year-old locomotive.

Schon Norris of the NRHS’s Promontory Chapter told the Standard-Examiner in an email that No. 5004 is one of only a handful of its kind ever produced.

“Utah Railway 5004 was built by Morrison-Knudsen in August 1995 — the fourth of six MK5000C prototype demonstrator locomotives,” he said. “As a demonstrator, its industry-first 5,000-horsepower capabilities were tested on the Union Pacific and Southern Pacific Railroads between 1994 and 1995, and later on BC Rail in Canada in 1998. It was subsequently tested by, and later sold to, Utah Railway in November 2000.”

According to the announcement of the acquisition on the Promontory Chapter’s Facebook page, issues with the original locomotive led to a rebuild.

Photo supplied, Schon Norris

“Due to drivetrain failures associated with the Caterpillar engine and Kato traction generator, 5004 was sent to Motive Power Industries in 2003 and converted into an MK50-3,” the post noted.

Norris said the locomotive would spend most of its revenue career with the Utah Railway.

“Post-rebuild, the locomotive spent the next decade and a half hauling unit coal, unit oil, and mixed commodity trains over the famed Soldier Summit route and along Utah’s Wasatch Front,” he said. “Following the decline in coal traffic on Utah Railway in 2017, 5004 and its siblings were relocated to the Kyle Railroad, a fellow Genesee & Wyoming property operating in Colorado and Kansas. It returned to its namesake state on July 21st, with subsequent delivery to the museum on July 26th.”

He said that plans are to evaluate restoration and future operational opportunities for the locomotive.

“With UTAH 5004 still working revenue trains through mid-2025, the locomotive has been reported to be mechanically capable of moving under its own power,” he said. “A full mechanical inspection will need to be completed before attempting to start it up. Cosmetically, there are a few holes to fill and the paint will need minor touch-ups, but otherwise it looks fantastic for an over 20 year old paint job.”

Photo supplied, Schon Norris

Hope Eggett, museum administrator for the Museums at Union Station, told the Standard-Examiner that the locomotive helps bring to life a part of the state’s rail history that has been somewhat underrepresented at the museum.

“Here at the museum, we have trains as old as the 1930s, but here at Union Station we don’t have as much of the new stuff from the last 30-40 years,” she said. “It’s wonderful to be able to host something that tells that part of the story and really emphasizes the Utah Railway’s long-lasting legacy.”

She said this isn’t the only Utah Railway locomotive to enter the collection, noting that the museum’s ALCO RSD-5 currently painted in Nickel Plate colors was once a part of the Utah Railway’s locomotive fleet.

Eggett said the plan is to house No. 5004 for the next two years.

With the locomotive type never making it into mass production, Norris said No. 5004 is an exciting find for the Promontory Chapter.

Photo supplied, Schon Norris

“As one of only six ever built, this locomotive type is considered a ‘unicorn’ by many in the railroad preservation industry,” he said. “Added on by the fact that these six ‘unicorns’ spent the majority of their working lives in the Beehive State. When thinking of the famed Utah Railway, many will point to the era of the ‘5000’s’ (the MK5000C/MK50-3’s) hauling long and heavy coal trains over the unforgiving Soldier Summit grade. Acquiring one for future generations was a no-brainer.”

He said that future fundraising opportunities for No. 5004’s restoration will be posted on the Promontory Chapter, NRHS Facebook page.

Utah Railway No. 5004 isn’t the only Promontory Chapter-owned locomotive on display and awaiting at Ogden Union Station following a late-career assignment to the Great Plains.

In November, Denver & Rio Grande Western Railroad No. 133 — a 1965-built EMD SW1200 — arrived at Ogden Union Station after it had spent several years working at a grain elevator in Beresford, South Dakota.

“Progress is slow but steady on the 133 at the moment,” Norris said. “The most notable change is that 133 got paired with a matching Rio Grande caboose at the museum, alongside the matching Western Pacific locomotive and caboose.”

Photo supplied, Schon Norris

D&RGW No. 133 is also on a two-year loan to the Utah State Railroad Museum with the intention to restore it to working order and find a future role for the locomotive.