Just off Interstate 280 near Los Altos and Cupertino, you will find a beautiful portrait of Californian landscape at Rancho San Antonio Open Space Preserve. Rancho San Antonio is woven with many different looping paths that form 23 miles of hiking and restricted biking and horseback trails that interlink the 3,800-acre sprawl of the Open Space Preserve with the 165-acre County Park. The County Park also protects the local Permanente Creek, a 13-mile creek that flows into Stevens Creek.
A stroll through the peaceful trails or the vast grassy fields will take one past a great variety of plant life. The woodlands of Rancho San Antonio are filled with trees such as Big-leaf Maple, Cottonwood, varieties of Oak, Willow, Douglas Fir, California Buckeye, and Bay Laurel trees. The County Park is also home to California's tallest and third-largest Bay Laurel tree (Umbellularia californica). Plant life in the area includes Chamise, Manzanita, birch-leaf mountain mahogany, sagebrush, monkeyflower, coffeeberry, and toyon.
Rancho San Antonio Open Space Preserve is home to a variety of wildlife. Some species found here include:
Mammals: Bobcat, Puma (Mountain Lion), Coyote, Gray Fox, Raccoon, Brush Rabbit, Western Gray Squirrel, Fox Squirrel, California Ground Squirrel, Merriam Chipmunk, Opossum, Black-tailed Deer. See the awesome video of a Puma (Mountain Lion) hunting a Black-tailed Deer below.
Birds: Over 380 species of birds inhabit Santa Clara County and many of them are found here with the exception of birds which are partial to the waters of the Bay. Some common birds you may see include Great Blue Heron, Red-tailed Hawk, Red-shouldered Hawk, White-tailed Kite, American Kestrel, Turkey Vulture, Wild Turkey, Calfornia Quail, Barn Owl, Great Horned Owl, Mallard, Ring-necked Duck, Acorn Woodpecker, Common Raven, Steller's Jay, California Thrasher, Blue-gray Gnatcatcher, Spotted Towhee, Lazuli Bunting.
Reptiles: Gopher Snake, California Kingsnake, Aquatic Gartersnake, Ringneck Snake, Western Yellow-bellied Racer, Western Rattlesnake, Western Fence Lizard, Southern Alligator Lizard, Western Skink, California (Tiger) Whiptail. There have been a few uncommon sightings of Coast Horned Lizard ...link .
Amphibians: Pacific Chorus Frog, Western Toad, California Newt
Fish: California Roach, Prickly Sculpin, Sacramento Sucker, Three-spined Stickleback. Historically, Rainbow and Steelhead Trout were present as well.
Butterflies: The varieties of butterfly seen changes with the time of year. Based on notes from Dave Bartholomew, here are seasonal patterns.
Before April - Mourning Cloak, Red Admiral, Painted Lady, American Lady, Satyr Anglewing
In April-May - Variable Checkerspot, Northern Checkerspot, Echo Blue, Pale Swallowtail, Veined White, Sara Orangetip, Umber Skipper, Mournful Duskywing, Propertius Duskywing
In summer - Western Tiger Swallowtail, Cabbage White, Acmon Blue, California Ringlet, California Sister, Lorquin's Admiral, Common Buckeye, Farmer Skipper, Mylitta Crescent
Late summer and fall - Common Checkered-Skipper, Woodland Skipper, Fiery Skipper
