Castle Rock State of Silicon Valley's original start ups.



Since our founders began in 1900, Sempervirens Fund has protected more than 34,000 acres of redwood forest. We hold in our hearts and minds the founders’ experience of what thrived here – and what can be restored through proper stewardship.

Like our founders, we work passionately to protect and connect the redwood forests into a vast and vibrant landscape that can support people and wildlife for countless generations to come.

Learn more about the remarkable people associated with the Santa Cruz Mountains throughout the years and those who have fought to protect it.

Join us Sept. 29, 2018 as we observe Castle Rock State Park's 50th Anniversary with a day-long celebration. Don't miss the grand opening of the park's brand new, state-of-the-art Robert C. Kirkwood entrance.

In 1968, Sempervirens Fund helped establish Castle Rock State Park. Today, the park encompasses 5,242 acres, boasts 34 miles of trail and contains some of the best bouldering routes in California.


From March 23 to March 25, 2018, Sempervirens Fund volunteers, the Amah Mutsun Land Trust Native Stewardship Corps and members of the Muwekma Ohlone joined forces to plant an ethnobotanical demonstration garden at Castle Rock State Park's new Robert C. Kirkwood entrance.