The Hieroglyphics roughly straddle the border between Maricopa and Yavapai counties and form an effective physical barrier northwest of the Phoenix Metropolitan Area.

[2] 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.

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.

[3] In 1928 a dam was constructed on the Agua Fria River where it passes through the mountain range, creating Lake Pleasant.