Chickasaw National Recreation Area

Though it now bears a title with much less gravitas, this beautiful landscape was once known by another name: Platt National Park.

Platt was the smallest national park in the system, but it drew big crowds. In 1914, it beat out the iconic Yellowstone and Yosemite National Parks for attendance. In the end, Oklahoma's only National Park was demoted.

Although the park is gorgeous, it isn't quite a natural wonder. In fact, many of its features were not the work of erosion or glaciers, but instead the work of the Civilian Conservation Corps (CCC). The CCC was brought in to build roads, plant trees, and reroute streams to beautify natural landscapes. They did their work incredibly well in Platt National Park, creating wonders such as the Little Niagara Falls, which stays a cool 65 degrees as it flows over the side of an outdoor pool.

The park lost its status in 1976, as the goal of the National Park system shifted from inviting tourists to preserving natural resources. The park still draws over a million visitors per year, all coming to explore the shaded streams and carefully built hiking routes that remain accessible.