Mount Burdell Open Space Preserve, Natural preserve in Marin County, California.

Mount Burdell Open Space Preserve is a 1,627-acre nature reserve managed by Marin County Parks. Its namesake peak rises 1,558 feet above sea level, and Hidden Lake, a seasonal pond about halfway to the top, holds water in the wet season. At least five quarries once operated on the mountain, the largest at the site of the Buck Institute, producing andesite paving blocks and highway materials.

The preserve was established in 1977 when the Marin County Open Space District acquired the land to protect the natural area. Local residents played an important role in this effort to preserve the landscape for public use.

Mount Burdell was the site of at least five quarries; the largest, at the present location of the Buck Institute, produced andesite paving blocks and materials for highway construction. Small herds of domestic cattle graze parts of the preserve in spring to reduce grasses.

The main routes include Eagle Rim Trail and Cobblestone Fire Road, suitable for both hikers and cyclists seeking different difficulty levels. Bring plenty of water since shade is limited in many areas and sun exposure varies along the trails.

Hidden Lake is a seasonal pond located midway to the summit that becomes a breeding ground for frogs and salamanders during wet months. This less-noticed water feature offers special opportunities to observe these animals during the rainy season.