This ridgeland between Corte Madera and Mill Valley was once proposed for a housing development, but was preserved and added to the Marin County Open Space District through the efforts of local residents.
The sight of horses peacefully grazing on this grassy knoll known as Horse Hill is one familiar to many Marin residents. Many people don’t realize the preserve is public open space. Thanks to a hard fought battle by local residents to save the hill from high-density housing development, the area is now permanently protected. The Alto Bowl Horse Owners Association holds a grazing lease from Marin County Open Space District to use the hill to graze their horses. Association volunteers have restored many acres of this preserve’s native habitats in an ongoing battle against French Broom and other invasive plants. They ask the public not to pet or feed the horses but instead, enjoy watching the horses from a safe distance. Hikers can take the Bob Middagh Trail starting at the bottom of the hill to connect to the expansive Camino Alto Preserve that stretches to the west of Horse Hill.