Join fellow train enthusiasts and ride in a vintage car pulled by a vintage locomotive on a day-long excursion from Salt Lake City to McCammon, Idaho and back. The dates are April 20 or 21.

Union Pacific's No. 3985 steam locomotive will pull the train. The locomotive is the largest operating steam locomotive in the country.Reserved seats are $100 per person, which includes a box lunch and entertainment. You can board in Salt Lake City at 7 a.m. or in Ogden at 8:30 a.m., and disembark in Ogden on the return trip at 5:30 p.m. or in Salt Lake City at 6:45 p.m.

Seats are assigned on a first-come, first-served basis. Make your reservations by calling 1-629-8444, or mail your check to Steam Trip 1991, P.O. Box 27272, Salt Lake City, UT 84127-0272.

The excursion will benefit Ogden's Union Station and the Promontory Chapter of the National Railway Historical Society.

Special to this excursion will be a museum car with a display designed by the Union Pacific Museum in Omaha, Neb. It will exhibit switchlocks from the Central Pacific Railroad, sawed-off firearms used to guard cabooses and express cars, dining car silver and china, a handcar, pocket watches, model trains and a bell, whistle and headlight from a steam locomotive.

Union Pacific's Challenger locomotive was conceived of by the railroad's chief superintendent of design and engineering. The first series of engines was built in 1936. The design was updated in 1941. Those locomotives have the 3900 classification. American Locomotive Company of Schenectady, N.Y., built 230 Challengers that were delivered to Union Pacific, Rio Grande and Northern Pacific railroads.

No. 3985 was delivered to Union Pacific on July 20, 1943. It cost $285,000. The railroad owned 105 of these giant locomotives. They pulled heavy freight loads over Wyoming's Sherman Hill Divide. They were also used in Utah's Wasatch Division.

They were used for heavy, fast passenger service, too.

No. 3985 was retired in 1962. It was displayed in front of the Cheyenne, Wyo., Union Pacific Depot in 1975. Restoration work began in 1978 and was completed in 1980. The engine is now used for railfan excursions and promotional events for Union Pacific.