Total Acres: 548
Total Expenditures: $0
Coyote Ridge is the first ridge rising from the east side of the Santa Clara Valley floor in the area between southern San Jose and Morgan Hill. The ridge runs predominantly northwest to southeast adjacent to Highway 101. The study area encompasses the western and eastern slopes of the ridge as far south as Anderson Lake County Park.
Serpentine grasslands dominate the ridgeline that reaches an elevation around 1,400 feet. In the furrows and folds of the hillsides are many small streams and seeps that support riparian plants and animals.
The western slope of the ridge feeds Coyote Creek, which flows toward the Guadalupe River and the bay. The northern portion of the eastern slope drains into Silver and Thompson creeks, which also flow northward. Further south, the eastern face of the ridge drains to San Felipe Creek and Anderson Reservoir.
The most significant natural feature of Coyote Ridge is its soil. Formed from serpentine, a rock with high concentrations of iron, magnesium and other minerals, the soil has low levels of plant nutrients and holds water poorly.
The plants that have developed a tolerance for these conditions form a community that includes more than a dozen rare or endangered species. These grasslands provide habitat for the threatened bay checkerspot butterfly (Euphydryas editha bayensis).
Protected lands within the study area include property managed by the Open Space Authority and other mitigation lands owned or managed by Silicon Valley Land Conservancy, William Lyon Homes, Castle & Cooke and Waste Management/Kirby Canyon.
To offset the impacts of highway projects in the area, the Santa Clara Valley Transportation Authority (VTA) purchased 548 acres of critical bay checkerspot butterfly habitat on Coyote Ridge. Setting aside the serpentine grasslands was just the first step.
The unique chemical nature of serpentine soil is no longer enough to protect its distinctive grasslands from the pressure of invading species. Increasing nitrogen levels in the air have helped introduced European plants like wild oats and Italian ryegrass to displace native annuals.
To counteract this process the land needs to be actively managed. An agreement between VTA and the Open Space Authority granting OSA a conservation easement and an endowment of $840,000 to care for the property in perpetuity will do that.
As part of the mitigation required by the U.S. Fish and Wildlife Service, the two agencies developed a comprehensive resource management plan. Goals of the plan include preserving and improving grassland resources, controlling invasive species and developing management strategies that can be adapted to changing conditions. Where appropriate, compatible recreation options will also be identified.
Much of Coyote Ridge, including the VTA property, is historic ranchland and is still being grazed. Cows are brought onto the land in late fall or early winter after the rains have begun and remain until late spring. The presence of cattle and their preference for the nitrogen-rich European grasses help create space for native plants to grow.
Controlled burning, herbicide treatments and mechanical removal are other methods of combating the invasive species that threaten the integrity of the Coyote Ridge serpentine grasslands. The importance and rarity of this environment cannot be overstated.
More than half the critical habitat identified by U.S. Fish & Wildlife Service for the bay checkerspot occurs on the ridge. The presence of microclimates there helps the butterfly survive fluctuations in weather conditions. This enables the Coyote Ridge population to help renew checkerspot communities that die out in other areas.
Wetlands on the property provide potential habitat for the California red-legged frog (Rana aurora draytonii) and California tiger salamander (Ambystoma californiense). Serpentine grasslands support a number of special-status plants including Mt. Hamilton thistle (Cirsium fontinale var. campylon), smooth lessingia (Lessingia micradenia var. glabrata), most beautiful jewelflower (Streptanthus albidus ssp. peramoenus) and the endangered Santa Clara Valley dudleya (Dudleya setchellii).
Beyond its importance as a refuge for rare and endangered species, Coyote Ridge is spectacular for its abundance of spring wildflowers and the diversity of wildlife. More than 200 plant species have been identified so far and animals sighted include elk, bobcats, badgers, coyotes, golden and bald eagles, horned larks, prairie falcons and American kestrels.