The Castle Mountains National Monument is located in the eastern Mojave desert in San Bernardino County, California, and is bordered on three sides by the Mojave National Preserve. The park was established in 2016 along with two other neighboring national parks, Mojave Trails National Monument, and Sand to Snow National Monument. Castle Mountain National Monument is the only park of the three that is managed by the National Park Service, and it protects 20920 acres of natural area and desert ecosystem, northwest of the Colorado River.
The monument surrounds an open pit gold mine, which will transfer to the park service when mining is completed. The main attraction in the park is the Castle Peaks, a group of spires that jut upwards, a unique geological formation that is popular with sightseers. Mojave desert grasslands, dense juniper forests, and Joshua trees lie at the foot of the mountains here. The stunning desert scenery is also habitat for area wildlife, and there are historical and archaeological sites in the area that are interesting to explore.
The park is open year round, there are no facilities at the park, no WiFi available, and cell phone reception is spotty. The visitor centre in the adjacent Mojave National Preserve provides information on the Castle Mountains National Monument area.