Hanging Rock and Wabash Reef is designated a National Natural Landmark, based on a program that was started in 1962 to encourage and support preservation of sites that illustrate geological and ecological history in the United States
Hanging Rock National Natural Landmark is a 4-acre (1.6 ha) site in Wabash County, Indiana that was designated a National Natural Landmark in May, 1986. The program was established on May 18, 1962, by United States Secretary of the Interior Stewart Udall. The program aims to encourage and support voluntary preservation of sites that illustrate the geological and ecological history of the United States. 
