A 7-inch gauge model of an actual Sacramento Northern electric railroad engine is on display through May 12, 2012 at the County History Center in downtown Martinez. Owned by Walnut Creek resident Eric Moe, who has driven it at Tilden Park among other places, the model is featured in celebration of the annual National Train Day, sponsored by Amtrak, to commemorate the anniversary of the completion of the first transcontinental railroad. Also on hand will be other members of the Walnut Creek Model Railroad Society to help visitors learn firsthand just how complicated it is to safely operate a railroad switching yard such as the one Union Pacific operates just west of downtown. The special event is part of the popular exhibit "Before BART: Electric Railroads Link Contra Costa County," which is open Tuesdays, Wednesdays and Thursdays from 9 a.m. to 4 p.m. and third Saturdays of the month from 10 a.m. to 2 p.m. through July 12, 2012. Admission is free.