Gary Giacomini Open Space Preserve
Managed by Marin County Parks
578 acres5.5 mi of trail
Hunt Camp TrailWillis Evans TrailBates Canyon Trail
Dog rules not recorded
No trailhead mapped yetWebsite ↗
–Not graded
Outdoors in San Geronimo
More than half of San Geronimo’s land is conserved: 66%
66% of San Geronimo’s land is conserved, about 637 acres. The biggest trail networks: Gary Giacomini Open Space Preserve (5.5 mi). 583 acres are parks and preserves, 1,000 per 1,000 residents.
Conserved land
66%
637 acres · of 1.5 sq mi of land
Trails
6.6 mi
4.4 per sq mi of land
Park land
583 ac
1,000 acres per 1,000 residents
Near a park
99%+
of residents within ½ mile
Highest peak
1,381 ft
Green Hill
Lakes & rivers
1
The map
Conserved land, trails & bike routes
Tap a number to zoom to a park. Tap a layer to hide it.
Easements protect land from building but are usually private.© OpenStreetMap contributors · USGS PAD-US
Places to walk
Pick a walk
The longest trail network is Gary Giacomini Open Space Preserve, with 5.5 miles. Directions go to the nearest trailhead or public parking.
San Geronimo Meadow
Managed by Marin Open Space Trust
8 acres0.3 mi of trail
Dog rules not recorded
No trailhead mapped yet
San Geronimo Park
Managed by Marin County Parks
8 acres
Dog rules not recorded
No trailhead mapped yetWebsite ↗
Mount Tamalpais Watershed
Managed by Marin Municipal Water District
1 acres0.1 mi of trail
Dog rules not recorded
No trailhead mapped yetWebsite ↗
Who protects it
637 conserved acres
66% of San Geronimo’s land. Who manages San Geronimo’s conserved land, from the USGS Protected Areas Database. Approximate, because parcels can overlap.
Regional agency636 ac
Land trusts & nonprofits8 ac
Regional Water Districts1 ac
Local Conservation Area · 566 acUnknown Easement · 55 acLocal Other or Unknown · 15 acLocal Park · 8 acLocal Resource Management Area · 1 ac
Good to know
Conserved doesn’t always mean open to visitors. 47 acres are conservation easements, usually private land. The walks above are places people visit.
The biggest protected parcels
| Parcel (PAD-US) | Managed by | Acres | Public access |
|---|---|---|---|
| Gary Giacomini Open Space Preserve Local Conservation Area | Regional agency | 566 | Open |
| San Geronimo Ridge Acq Local Other or Unknown | Regional agency | 15 | Open |
| San Geronimo County Park Local Park | Regional agency | 8 | Closed |
| Marin Municipal Water District Watershed Local Resource Management Area | Regional Water Districts | 1 | Open |
Things to do
2 places to go in San Geronimo
Beaches, playgrounds, peaks, falls and more. Pick a kind.
Peaks in San Geronimo
Green Hill1,381 ft elevation · In Gary Giacomini Open Space Preserve
DirectionsPicnic areas in San Geronimo
Hunt CampIn Gary Giacomini Open Space Preserve
DirectionsTrails & water
4 named trails and 1 lakes & rivers
Named trails
Unpaved · 2.0 mi
Hunt Camp Trail1.4 mi
Willis Evans Trail0.7 mi
Chaparral Lane Trail0.1 mi
Bates Canyon Trail0.1 mi
Lakes & rivers tap for directions
Biking & sports
0.0 miles of bike routes
Bike lanes are often missing from the map in smaller towns, so that number is likely low.
Courts & fields
1Tennis
Includes school and college facilities, which aren’t always open to the public.
When to get out
The best walking months in San Geronimo: April to August
NOAA’s 1991–2020 normals for the town and the daylight at its latitude. Outlined months have long days, highs of 59 to 86 °F and little rain for the place.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 9.8 | 10.7 | 11.8 | 13.1 | 14.2 | 14.8 | 14.6 | 13.6 | 12.4 | 11.1 | 10.1 | 9.5 |
| High (°F) | 56 | 58 | 61 | 63 | 67 | 73 | 76 | 77 | 77 | 72 | 62 | 56 |
| Rain (in) | 7.4 | 7.2 | 5.2 | 2.5 | 1.2 | 0.3 | 0.0 | 0.1 | 0.1 | 1.8 | 4.0 | 8.1 |
July is the driest month (under 0.1 in) and August the warmest (highs of 77 °F). 8.1 inches fall in December, the wettest month. The climate in San Geronimo →
Next door
San Geronimo and its neighbors
Tap a town to see its outdoors.
| Town | Conserved of land | Trail mi per sq mi | Park acres per 1,000 | Near a park ½ mile | Outdoors |
|---|---|---|---|---|---|
| San Geronimo | — not graded: under 1,000 residents or part of its town | ||||
| Woodacre | 36% | 5.0 | 256 | 99%+ | A+ |
| Lagunitas-Forest Knolls | 42% | 4.8 | 707 | 99%+ | A+ |
The four inputs of the Outdoors grade, from the engine; shares are of land, not water.
Questions about parks and trails in San Geronimo
Where can I hike in San Geronimo?
The longest trail networks: Gary Giacomini Open Space Preserve, 5.5 miles; San Geronimo Meadow, 0.3 miles; Mount Tamalpais Watershed, 0.1 miles. Each one is on the map above, with directions to the nearest trailhead or parking.
Are dogs allowed on San Geronimo’s trails?
Gary Giacomini Open Space Preserve and San Geronimo Meadow don’t have dog rules recorded on the map; check the signs at the trailhead.
Is there public land near San Geronimo?
82,186 acres of parks and open public land lie inside San Geronimo or within 10 miles of it (PAD-US), 583 of them inside the town line.
Trail talk
Conditions, parking and favorite walks from San Geronimo neighbors.
Share a tip
Sources
Where this page comes from
Conserved and public land: USGS Protected Areas Database of the United States (PAD-US), service updated July 2026. Parks, trails, playgrounds, beaches and other places: OpenStreetMap (© OpenStreetMap contributors, ODbL), map data as of 2026-10-28. Land and water area: Census 2025 Gazetteer. Residents near a park: 2020 Census blocks. National Register: National Park Service. How TownRatings grades the outdoors →