During the Great Depression of the 1930s, the Civilian Conservation Corps established a camp here to improve the park, employing 200 men at a time and providing much needed jobs and training. Over eight years, these young men helped build the visitor center, built concrete stairs in the cave, and helped sink the 212-foot elevator shaft. They also graded roadsides, planted trees, built trails, and served as fire lookouts. In addition to room, board, and clothing, they received $30 a month, most of which was sent home to their families. Many buildings in this area are now listed on the National Register of Historic Places as a tribute to the CCC's enduring work.