Overview
Rancho San Antonio Open Space Preserve sits on roughly 4,000 acres straddling the border of Cupertino and Los Altos Hills in Santa Clara County. Managed by the Midpeninsula Regional Open Space District (MROSD), it is one of the most visited open space preserves in the Bay Area, drawing hikers, runners, cyclists, and wildlife watchers from across Silicon Valley and beyond.
The preserve contains a patchwork of habitats: rolling grasslands, dense coast live oak forests, riparian corridors along Permanente Creek and its tributaries, and exposed ridgeline chaparral. This diversity supports a wide range of wildlife, including deer, coyotes, red-tailed hawks, and the occasional mountain lion.
A working farm — Deer Hollow Farm — sits within the preserve and provides an agricultural and nature-education program, particularly popular with families and school groups. Its presence gives the preserve an unusual dual character: part working heritage landscape, part wildland.
The trail network connects to the broader Santa Cruz Mountains trail system, and fit hikers can link up with Monte Bello Open Space Preserve or Black Mountain via longer routes. This connectivity makes Rancho San Antonio a genuine trailhead for multi-preserve adventures, not just a neighborhood park.
Before You Go
No entrance fee is charged to enter the preserve itself; parking at the main Rhus Ridge Road and Cristo Rey lots is free (verify current status on the MROSD official site, as demand sometimes prompts management changes). Arrive early on weekends and holidays — the primary parking areas fill by mid-morning, especially in spring.
Key things to check before visiting:
- Current trail conditions and any seasonal closures on the MROSD website (openspace.org)
- Deer Hollow Farm hours, which vary by season and may require advance registration for programs
- Fire-season restrictions, which can limit trail access during high-risk periods
- Dog policy: dogs are not permitted on trails within Rancho San Antonio Preserve; they are allowed on a leash in the adjacent Rancho San Antonio County Park paved areas
Download a trail map before you go — cell coverage can be inconsistent in the lower canyon sections. The MROSD app and AllTrails both carry accurate maps of the preserve.
Getting There
By Car
The main preserve entrance is off Cristo Rey Drive in Cupertino, reachable from Interstate 280 via the Foothill Expressway / Cristo Rey Drive exit. GPS coordinates for the main parking lot are widely available in mapping apps. A satellite county park parking lot with an overflow pedestrian connection also exists nearby.
By Public Transit
VTA (Santa Clara Valley Transportation Authority) bus routes serve the general Cupertino–Los Altos Hills corridor. Verify current route numbers and stop locations on the VTA website or 511 SF Bay, as schedules change. The preserve is not immediately adjacent to a bus stop, so expect a short walk from the nearest stop.
By Bicycle
Several regional bike routes connect to the area via Foothill Expressway and adjacent roads. Note that bicycles are permitted on designated multi-use trails within the preserve but are prohibited on single-track footpaths — check the MROSD trail map for bike-legal routes before planning a cycling itinerary.
Getting Around
The preserve is navigated entirely on foot (or bicycle on permitted trails). There is no internal shuttle or motorized access beyond the trailhead parking areas. Trail distances range from short loops under 2 miles to full-day routes exceeding 10 miles when combined with connecting preserves.
The most popular loop — often called the PG&E Trail / Wildcat Loop — covers roughly 5–6 miles and gains several hundred feet of elevation, offering meadow, woodland, and partial Bay views. Signs at trail junctions are generally clear, but intersections can be confusing; carry a downloaded map.
Trails are typically well-maintained dirt paths. Some sections become muddy and slippery after rain; check conditions before visiting in winter and early spring. Sturdy trail shoes or light hiking boots are recommended over casual sneakers for anything beyond the flat lower meadow paths.
Things to See & Do
Hiking
With over 24 miles of trails, hiking is the primary activity. Beginners favor the flat, wide paths around the meadow and along Permanente Creek near the trailhead. Intermediate and experienced hikers head uphill on the PG&E Trail toward Black Mountain or onto Chamise Trail for ridge views and woodland solitude.
Deer Hollow Farm
This working farm demonstrates historic California agricultural practices and keeps a small collection of farm animals. It functions as an environmental education center; drop-in visitors are often welcome during staffed hours, though programs and tours may require registration. Verify current hours and access directly with MROSD.
Wildlife Watching
The oak woodland and grassland transition zones are productive for birding, particularly in fall and winter when migratory species pass through. Early morning is best for spotting deer and raptors. The creek corridor supports herons and kingfishers year-round.
Running
Rancho San Antonio hosts a devoted trail-running community. The varied terrain — from flat creek paths to steep ridge climbs — suits runners of all abilities. Several local running clubs hold regular group runs here; verify schedules locally.
Photography
The preserve offers appealing landscape photography opportunities in all seasons: wildflowers from February through April, golden grasslands in summer, and fog-draped oaks in winter.
Food & Drink
There are no food vendors, cafés, or restaurants within the preserve. Bring all food and water you expect to need. Water refill stations may be available near the trailhead — verify on the MROSD site before relying on them.
For meals before or after your visit, the Cupertino and Los Altos commercial corridors along Stevens Creek Boulevard and State Street respectively offer a wide range of options, from casual cafés to sit-down restaurants. The Silicon Valley dining scene at this edge of Cupertino is diverse, reflecting the area's multicultural population.
Pack out all food waste; the preserve has limited waste infrastructure and wildlife habituation to human food is an ongoing management concern.
Practical Information
Restrooms: Portable or permanent restroom facilities are located near the main trailhead parking area. Verify availability on the MROSD site, as infrastructure can change.
Cell service: Intermittent throughout the preserve. Download maps and emergency contacts before entering.
Weather: The microclimate in the lower canyons can be significantly cooler and damper than surrounding flatlands. Bring layers even on warm days. Morning fog is common spring through early summer.
Leave No Trace: The preserve operates under strict LNT principles. Stay on marked trails to protect sensitive vegetation; do not pick wildflowers or disturb wildlife.
Dogs: Prohibited on all preserve trails. Leashed dogs are permitted in portions of the adjacent Santa Clara County park. Verify boundaries carefully before bringing a dog.
Emergency contact: In a serious emergency, call 911. The MROSD Ranger Patrol can also be reached through contact information listed on the official MROSD website.
Safety
Mountain lions are present in the Santa Cruz Mountains ecosystem that includes this preserve. MROSD posts standard mountain lion safety guidelines at trailheads; read them before hiking. Do not run alone at dawn or dusk, keep children close, and know how to respond if you encounter one.
Rattlesnakes are common in the grassland and chaparral zones, particularly from spring through fall. Watch where you step and place your hands, and stay on trail. Most encounters are uneventful if you give the animal space.
Poison oak is widespread throughout the preserve, especially in the oak woodland understory and along creek banks. Learn to identify it ("leaves of three, let it be") and wear long pants and long sleeves if you are sensitive. Wash exposed skin and clothing after visits.
Heat-related illness is a real risk for hikers who arrive unprepared in summer. Carry more water than you think you need, start early, and turn back if you feel overheated. The exposed upper ridge sections offer little shade.
