The mission of the Peninsula Open Space Trust (POST) is to give permanent protection to the beauty, character and diversity of the San Francisco Peninsula and Santa Cruz Mountain range. POST encourages the use of these lands for natural resource protection, wildlife habitat, low–intensity public recreation and agriculture for people here now and for future generations.

Since its founding in 1977, POST has been responsible for saving 60,000 acres as permanent open space and parkland in San Mateo, Santa Clara and Santa Cruz counties.