Castle Rock Regional Recreation Area is bordered by: Diablo Foothills Regional Park on the west, and Shell Ridge Open Space to the north. Together, these three parks provide 18,000 acres (73 km2) of parkland for visitors to enjoy. [1]
Recreation and Activities
Castle Rock Regional Recreation Era is an attraction for many outdoor activity opportunities such as hiking, climbing, swimming, and viewing wildlife. A portion of the park is closed every year for several months in order to protect a peregrine falcon nesting site.[1] Rock formations such as Castle Rock are popular hiking destinations for hikers of all levels and also provide climbing routes for outdoor boulderers and rope climbers.
History
Around 33 to 55 million years ago, the ancestral Sierra Nevada experienced weathering due to a warming climate, which led to the deposition of sandy sediments into an inland sea in the Central Valley. This created shallow marine basins and tidal marshes. The sandy rock formations that resulted are visible along the southern and western sides of Mount Diablo at locations like Castle Rock.[2]