Oklahoma Railway Museum  
3400 Northeast Grand Boulevard
Oklahoma City, OK 73111
405-424-8222

The museum has passenger, freight, and engines on display and artifacts from actual depots from the glory years in Oklahoma. They have ORM merchandise (HO Scale Trains, Cups, Mugs, Hats, etc) and are open to public viewing every Saturday from 10-4 p.m. They also offer train excursions from April through October on every third Saturday.