The Locomotive Operators of Central Oklahoma (LOCO) is a nonprofit organization dedicated to promotion and enjoyment of large (1/8th, to be exact!) scale model railroading.
Their rail is located just off of Shawnee's Twin Lakes and is open once a month for public rides, and can also be booked for parties of all kinds.
Open to the public (no reservation needed!) on the first Sunday of every month, from 1 - 4 pm, as well as special events like Train Rides with Santa in December of each year.