The collection focuses on Southern California's railroad history and houses the largest collection of Pacific Electric Railway rolling stock in the world, much of it rescued from scrapyards after the discontinuation of their passenger operations.
Two early Los Angeles narrow gauge streetcars from the Los Angeles Railway run each weekend on the half-mile long, dual gauge "Loop Line" while a passenger-carrying diesel or electric freight train with open gondolas fitted with benches and at least two cabooses runs on the 1.5-mile (2.4 km) long, standard gauge mainline that was once an abandoned spur line of the Santa Fe Railroad. The main stretches from just south of the property northward to the junction with BNSF Railway where the historic Santa Fe depot on Highway 74 stands. The BNSF Railway spur is still in active use, and the railroad grants permission for OERM trains to use the spur for special events. A Pacific Electric interurban "Red Car" also operates on the mainline on selected weekends, but the line is electrified only as far as a block south of the depot. Streetcars and locomotives are selected on a rotating basis. The museum maintains a steam locomotive in operating condition and its use is scheduled for certain special events and major holidays.
Both admission to the OERM and parking are free except for special events, but a ticket must be purchased to ride on the museum railway. The ticket is good for unlimited rides on the train and streetcars.
Tours of the grounds, static exhibits and shops are self-guided. A picnic area is located near the main entrance as is an interactive railroad "signal garden." The signal garden has working examples of block signals and grade crossing signals, including two working examples of the "wigwag" grade crossing signals once common throughout California.