The Castle Dome Mountains (Tolkepaya Yavapai: Wi:hopuʼ) are a mountain range in Yuma County, Arizona, within the Kofa National Wildlife Refuge. Castle Dome Peak, the high point of the range, is a prominent butte and distinctive landmark. The peak is 3,776 feet (1,151 m) high, and is located at 33°05′04″N 114°08′36″W / 33.08444°N 114.14333°W. Castle Dome was named by American soldiers at old Fort Yuma in the 1880s. Early Spanish explorers called the same peak Cabeza de Gigante, "Giant's Head."