The three counties of Marin, Napa, and Sonoma contain some of the most abundant acreage of open space in the state. The most common definition of what that means is protected land that is not as developed for recreational purposes as state or city parkland. Not all such protected lands offer public access, but most do. And some open space land has agricultural use grandfathered in, having historically been used for that purpose. The open space lands in our counties have been either donated by families or purchased by organizations such as The Nature Conservancy or County Land Trusts.
A few years ago, when the tally was made, Marin had 34 open space preserves that offer hiking trails and scenic vistas as well as wildlife viewing and natural amenities such as waterfalls, rock formations, and redwood groves. Since 1972, the Marin County Open Space District has acquired over 16,000 acres of marshland, forests, creeks, and rolling hills. They include over 250 miles of unpaved roads and trails made from former logging and ranch roads, as well as fire protection roads.
This District organization is managed by the Marin County Parks department, which also manages 19 parks owned by the county.
· Baltimore Canyon: At the headwaters of Larkspur Creek, this 193-acre preserve encompasses a canyon filled with stately trees and a spectacular waterfall. Blithedale Ridge Rd., Kentfield
· Cascade Canyon: It incorporates 504 acres of some of the most pristine habitat in the Corte Madera watershed. The falls at the head of the main canyon, in the hills about Fairfax, are a popular destination when at peak flow in spring and winter, Fairfax.
· San Pedro Mountain: Trails from nearby parks lead to this ridge, San Rafael.
· Gary Giocomini: This 1,500-acre nature preserve offers hiking and biking on rugged terrain, Forest Knolls.
· Loma Alta: Running along the lower perimeter of the preserve is the Old Railroad Grade of the Sunrise Fire Road, Fairfax.
· Ring Mountain: This windswept ridge atop the Tiburon Peninsula is one of the most valuable pieces of real estate in our region, if not the country.
county’s Ag + Open Space organization has protected 116,000 acres of land since
1990; 20,000 acres of that land are accessible to the public as open space
preserves. The preserves are described under the county’s Open Space and
Resource Conservation Element in its Land Use Plan.
· Taylor Mountain: Offers 5.5 miles of multi-use trails for hikers, mountain bikers, and horseback riders, as well as an 18-hole golf course, Santa Rosa.
· Clover Springs: This 5.6-acre open space area offers hiking and walking and is located along Skyview Drive, Cloverdale.
· Healdsburg Ridge: This 155-acre property supports 40 bird species and rare plants like serpentine rye grass, as well as bobcats and mountain lions. It’s at Bridal Path and Arabian Way, Healdsburg.
· Montini: Offers open grassland, an historical rock quarry, and oak woodland, with views of Sonoma Valley and both San Francisco and San Pablo bays. The ranch existed since the time of General Mariano Guadalupe Vallejo. Trailheads at 1st St. West and 4th St. West. Preserve address: Norrborn Rd., Sonoma.
· North Sonoma Mountain: This 820-acre preserve stretches from south of Bennett Valley to the western boundary of Jack London State Historic Park in Glen Ellen. The entrance is 5 miles southeast of Santa Rosa at 5297 Sonoma Mountain Road. The preserve includes a four-mile section of the Bay Area Ridge Trail. Its trails are open to hikers, bikers (first two miles only), and pedestrians.
The county’s Regional
Park and Open Space District manages the day-to-day operations of 10
locations in Napa County that are open to the public, including parks and
preserves, notably Bothe Napa Valley State Park, the Bale Grist Mill State
Historic Park, Robert Louis Stevenson State Park, Oat Hill Mine Trail, and
Moore Creek Park. Altogether, 5,000 acres are protected. Visit napaoutdoors.org
to see locations of these areas.
The county defines open space as those lands which are
primarily either undeveloped or developed only with improvements which are
necessary or ancillary to “the preservation, stewardship, and appreciation of
natural, cultural, and archaeological resources, the protection of water
quality and quantity, the raising of food and fiber, and the provision of
The District has recently completed six more projects, which fit the definition of open space:
· Smittle Creek: With the purchase of 443 acres west of Lake Berryessa at the creek, the public will be able to explore the previously inaccessible 6,500 acres of Cedar Roughs Wilderness.
Amy's Grove: 51 acres on Dry and Wing Creeks in the Mayacamus Mountains have been protected.
Lake Berryessa: The “donut hole” at the lake has been protected in partnership with the Napa County Land Trust (a private inholding between District and federally owned lands), thereby creating a 784-acre contiguous wilderness preserve and opportunities for hiking and backcountry camping. Also completed phase 1 of Berryessa Camp for youth education and camping experiences.
Soscol Headwaters: Completed first phase of this plan with the purchase of 411 acres, resulting in five miles of new Bay Area Ridge Trail. connecting Skyline Park to Highway 12 in Jameson Canyon.
· Spanish Valley, Crystal Flats, and Stone Corral: Located in Pope Valley and gifted to the District by the Trinchero Family. ·
Montesol: 7,000-plus acres donated by the Livermore family as a conservation easement in 2016 to the Napa County Land Trust and the Trust for Public Land. As part of the agreement, the District can purchase the 1,254 acres of property located west of Highway 29 and open it for public access, creating the first summit route to the top of Mount St. Helena outside of the fire service road currently in use.
Legal Definition of Open Space Land
To answer the original question in more detail, open space land is defined as:
(1) Any land area zoned for open space by a comprehensive land use plan adopted by a city or county legislative authority, or
(2) Any land area in which the preservation in its present use would:
- Conserve and enhance natural or scenic resources
- Protect streams or water supply
- Promote conservation of soils, wetlands, beaches, or tidal marshes
- Enhance the value to the public of abutting or neighboring parks, forest, wildlife preserves, nature reservations or sanctuaries or other open space
- Enhance recreation opportunities
- Preserve historic sites
- Preserve visual quality along highway, road, and street corridor or scenic vistas
- Retain in its natural state tracts of land not less than one acre situated in an urban area and open public use on such conditions as may be reasonably required by the granting authority.
County open space district websites