O’Shaughnessy Hollow

The Marietta rocks in O'Shaughnessy Hollow

This steep cliff towering above O’Shaughnessy Boulevard has beautiful grasslands and magnificent rocky outcrops. The folds and fractures within the chert are some of the most dramatic in San Francisco. Although technically a different park, O’Shaughnessy Hollow is only separated from Glen Canyon by a road, and its grassland and scrub plant communities are quite similar. See the description of Glen Canyon Park for more information.

In the early 1980s the area was considered for a development of 16 single-family homes. Ultimately these parcels were purchased by the City and County of San Francisco with open space funds to preserve the area’s natural biodiversity.