Early human settlement in the Hieroglyphic mountains is sparse at best. Existing petroglyphs indicate that the area had been settled, or at least visited, by
Native Americans prior to the 19th century. A
gold strike on the
Colorado River near
Yuma in 1862 created local interest in prospecting, and the Hieroglyphics were among many of the local mountain ranges visited by prospectors during this time period, but the ruggedness of the terrain and the scarcity of water largely discouraged permanent settlement. In the early 19th century, local
Yavapai Indians had discovered a natural
hot spring in the mountains, treating the location as a sort of "demilitarized zone" where all were welcome to come and treat their wounds. The springs were discovered by
US Army Colonel
Charles Craig in 1867 while pursuing a group of Yavapais through the mountains. The group named the spring Castle Springs for the
castellated appearance of the surrounding mountains. While most sources credit Craig with the discovery, some sources claim that the springs were first discovered by a gold miner in 1874.
Ongoing fighting between the US Army and the Yavapai tribes would discourage further development of the area until the 1880s when the springs and the adjacent land were purchased by Frank Murphy for the construction of a
health resort. The resort was completed in 1896 and the newly renamed
Castle Hot Springs were heavily advertised to potential clients. During the resort's heyday in the 1920s it was extremely popular and was visited by celebrities such as
Zane Grey, as well as famous families such as the
Rockefeller family. The resort was also used by the United States military as a rehabilitation center from 1943–1944 to treat injured veterans of
World War II. Future president
John F. Kennedy spent 3 months at the resort during this time period to recover from his wounds. The resort continued to be popular until it was heavily damaged in a fire in 1976. In 1928 a dam was constructed on the
Agua Fria River where it passes through the mountain range, creating
Lake Pleasant. The lake was primarily used as an agricultural storage facility, but with the creation of the
Central Arizona Project in 1973 the lake became a permanent water storage facility and an important recreational center. The dam was replaced in 1993, increasing the size of the lake. ==Geography==