Keystone Free-MO (KEY-MO) is an HO scale modular group following the Free-MO standard.

The mission of Keystone Free-MO is to attract existing model railroaders, in the age 25-45 demographic, who are ready to take the next step beyond simply operating model trains, and into a more engrossing exploration of railroad history, and the enjoyment that can be attained from modeling a prototype railroad such as the Pennsylvania Railroad — once the largest corporation in the world — and to generate membership in the Pennsylvania Railroad Technical & Historical Society.

The vision of Keystone Free-MO is to bring together like-minded hobbyists to construct, display, and operate a portable model railroad which will differentiate the modeling of the Pennsylvania Railroad from other railroads through the demonstration of its physical plant, diverse motive power, signaling systems, and other unique aspects. The group will encourage scholarly interest in the railroad through membership in the Pennsylvania Railroad Technical & Historical Society so that participants might better understand the contributions of the railroad to the industry and the growth of the country.

A core group of members has created standards that append the existing Free-MO standards to allow for Pennsy three- and four-track rights-of-way. The group models the railroads radiating out of York, Pennsylvania.

Junctions along the main line join to standard Free-MO modules to represent branch lines or interchange roads. We interoperate with Philly FreeMO and Capitol FreeMO.

To follow the group's public progress, "like" the FaceBook page at

To participate, visit the Yahoo Group at and contact the list owner. This group is for active participants only, and not for "spectators." You will be asked how you plan to contribute.