Mount Diablo, Calif. — On Saturday, July 18, 2026, California State Parks and the Mount Diablo Surveyors Historical Society will commemorate the 175th anniversary of the Mount Diablo Initial Point with a day-long public celebration highlighting the history and enduring importance of one of the West’s most significant surveying landmarks.

The free educational event will be held from 10:00 a.m. to 4:00 p.m. at the Summit Upper Lot in Mount Diablo State Park. Visitors of all ages are invited to experience interactive exhibits, historical surveying demonstrations, educational presentations, and family-friendly activities that illustrate the vital role surveying has played in the development of California and Nevada.

The celebration will feature presentations exploring the history of Mount Diablo and the Public Land Survey System, demonstrations of historic surveying equipment and techniques, hands-on exhibits showcasing the science and practice of land surveying, and activities designed to introduce younger visitors to the profession.

Visitors are encouraged to bring lunch, snacks, drinks, and sunscreen and plan to spend the day enjoying the mountaintop setting while learning about one of California’s most enduring historical landmarks.

The event will take place at the Summit Upper Lot. Parking is available throughout Mount Diablo State Park, with the lower parking lot offering the greatest capacity, along with restrooms and picnic facilities. The drive to the summit from either the North Gate or South Gate entrance is approximately 45 minutes. Standard park admission of $10 per vehicle applies.

The anniversary celebration is presented by California State Parks in partnership with the Mount Diablo Surveyors Historical Society and the Mount Diablo Interpretive Association.

For additional information, visit www.mdshs.org or email mdshsorg@yahoo.com.