In March 1776, Juan Bautista de Anza led the first overland expedition to San Francisco Bay from Monterey through this area.

In de Anza's diary on March 25, 1776, he states that he "arrived at the arroyo of San Joseph Cupertino (now Stevens Creek), which is useful only for travelers.

"[2] A prominent hill between Permanente and Stevens Creeks is referred to as "De Anza's Knoll" and marks the location where the explorer first spotted the Bay.

In 1923, the Catholic Church purchased what had become the Snyder Ranch and in 1926 constructed Saint Joseph's College and the Maryknoll Seminary.

On hotter, south-facing slopes, chaparral scrub of chamise, manzanita, and birch-leaf mountain mahogany predominates.

West Branch Permanente Creek begins on the east side of 1,253-foot Ewing Hill, and runs easterly until it reaches the connector from the Chamise and Rogue Valley Trails where an earthen dam forms High Meadow Pond (aka Rogue Valley Pond).

West Fork Permanente Creek and its Wildcat Canyon tributary flow intermittently in summer and fall.

The Permanente riparian corridor is crucial for wildlife survival, providing food and water as well as the ability to migrate through suburban areas relatively undisturbed.

Along with deer, other commonly seen animals are California quail, cottontail rabbits, crows, hawks, jays, LBBs (little brown birds), lizards, squirrels, turkeys, voles, white tailed kites, woodpeckers.

Less common, reclusive, or seasonal are blue herons, butterflies, California slender salamanders, coyotes, egrets, frogs, gopher snakes, jackrabbits, newts, rattlesnakes, skunks, tarantulas.

Star Thistle is an invasive species growing prolifically in the meadows and along sunny trail sides in the park and the preserve.

The State's tallest and third largest California bay laurel tree (Umbellularia californica), estimated to be over 200 years old, grows in Rancho San Antonio County Park.

The 150-year-old Farm covers ten acres and stands as a reminder of Santa Clara County's agricultural history.

The Deer Hollow Farm section of the Rancho San Antonio land preserve is managed by the City of Mountain View recreation division.

These programs include a Nature center, which is housed in an old apple shed (one of the original 1850s buildings), School Year Classes for kindergarten through fifth graders, which offer farm and garden education, exploration of the wilderness preserve, Ohlone Indian education, and Summer Wilderness Camps for children in grades one through nine which encourage exploration of the preserve and hands-on learning.

The extent to which visitors utilize the open space preserve shows how important it is to the Silicon Valley community.

[8] Five picnic tables with charcoal bar-b-q stands are located at the south end of the North Meadow in the County Park.

The easternmost entrance to the County Park is 0.3 miles (0.48 km) from North Foothill Blvd, on Cristo Rey Drive.

Pedestrian access is also available at Mora Drive and Ravensbury Avenue in Los Altos Hills as well as Black Mountain Trail from Monte Bello Open Space Preserve.