the Union Pacific "Big Boys", are preserved, including one overlooking Omaha, Nebraska where UP is based. In January 2014, Big Boy #4014 was removed from its museum ground parking track in Pomona, California, and hauled to Cheyenne, Wyoming, for restoration to operating condition; this was completed in May 2019. No. 4014 is the largest, heaviest, and most powerful operational steam locomotive in the world. Two of Union Pacific's Challengers survived into preservation. Challenger #3985 was the largest operational steam locomotive in the world until the restoration of UP 4014. It was taken out of service in October 2010 due to mechanical problems and retired from the Union Pacific's excursion program in January 2020. As of January 2023, No. 3985 is being restored to operating condition by the Railroading Heritage of Midwest America. Chesapeake & Ohio 2-6-6-2 #1309, the last domestic steam locomotive built by Baldwin, was scheduled for restoration in September 2017. "New as they were, the last C&O steam engines never got adequate maintenance, lengthening the list of work needed to bring 1309 back to life." The locomotive was fired up and moved under her own steam on December 31, 2020, the first time she had done so in 64 years. On December 17, 2021, C&O 1309 (now WMSR 1309) entered excursion service on the Western Maryland Scenic Railroad. The single surviving example of a cab-forward Mallet is Southern Pacific 4294, on display at the California State Railroad Museum in Sacramento, California. Several smaller logging-railroad Mallets have been restored to operating condition, including Black Hills Central #110 in Hill City, South Dakota, Clover Valley Lumber Company #4 in Sunol, California, and Deep River Logging "Skookum" #7 in Garibaldi, Oregon. CC 50 22, an early Dutch-built Indonesian Mallets has been returned to the Netherlands and is now exhibited in the Dutch Railway Museum but meanwhile, the other 2 like CC 50 01 is preserved in Transportation Museum in TMII and CC 50 29 is preserved in the Ambarawa Railway Museum. Another industrial type has been purchased and restored by the Statfold Barn Railway in the UK. This saw its first operation in Europe in 2011 and after initial trials on the owners' railway, was transferred to the Welsh Highland Railway as its power is better suited to that railway. A number of Mallets were constructed for the Nordhausen Wernigerode Eisenbahn, now part of the Harz Narrow Gauge Railways system in