During the mid 1940s or prior, partners in the park had a falling out. The result was the separation of the park into two adjacent parks separated by a concrete wall that shared essentially the same name. The northwestern side (Rocky Glen Park) was owned by the Nallin-Jennings Park Company and was accessible by a public road. The southeastern portion (Sterling's Rocky Glen Park) was owned by Ben Sterling and his wife (operating as Glen Amusement Company) and was accessible primarily by rail.
By 1949, each park had a carousel, a roller coaster, a restaurant, bath-houses on the lake frontage and bumper cars. The 1950 fire destroyed Sterling's penny arcade, the coaster, funhouse and Tokio Canals ride owned by Nallin-Jennings. The following year, Sterling bought out his competitor, combined the parks and disposing of duplicate rides.