The Open Space Preserve, combined with the adjoining County Park, in area and contains of hiking trails. A one-mile walk from the County Park's main parking lot leads to the historic 10-acre Deer Valley Farm on the West Fork Permanente Creek. There is a trail that runs along the creek, beginning at the historic Rengstorff House in Shoreline Park where it is connected to the San Francisco Bay Trail. The Permanente Creek Trail runs from there south to West Middlefield Road.