Kimball was an avid railway enthusiast and donated his narrow gauge collection to the Southern California Railway Museum (formerly the Orange Empire Railway Museum) in Perris, California. A full-size steam locomotive, which Kimball ran on his private backyard railroad known as "Grizzly Flats Railroad" in San Gabriel, California, bears some of his original artwork on the headlamp and cab, and is on permanent display at the museum. Kimball's roundhouse also included two small steam engines that had been used on sugar cane plantations, one of which was his and the other was owned by his friend, noted railroad historian Gerald M. Best. In recognition of his love of railroading and support of the Southern California Railway Museum, the Perris Transit Center, where the museum's historic trains travel, is dedicated to Mr. Kimball. In a rare deviation from its usually tight copyright policy, the Disney corporation allowed the city to decorate the transit center with Kimball's artwork. The center is currently served by Riverside Transit Agency buses, with train service as part of the Metrolink Perris Valley Line.