“The last of the Coast Range foothills were in near view all the way to Gilroy. Their union with the valley is by curves and slopes of inimitable beauty, and they were robed with the greenest grass and richest light I ever beheld, and colored and shaded with millions of flowers of every hue chiefly of purple and golden yellow; and hundreds of crystal rills joined songs with the larks, filling all the valley with music like a sea, making it an Eden from end to end…”
—John Muir, 1868 on his walk from San Francisco to Yosemite Valley.

While much has changed since John’s day, this scene can still be experienced in the foothills surrounding the southern Santa Clara Valley. An archipelago of flower-filled serpentine grasslands, with ~7000 contiguous acres on Coyote Ridge and disjunct smaller islands to the north, south, and west, support more than a dozen rare, threatened, and endangered species, including the iconic Bay checkerspot butterfly. Herds of tule elk graze peacefully along with cattle in sight of Highway 101 and the southern reaches of Silicon Valley.

As of 2010, ~500 acres of serpentine grassland on Coyote Ridge were conserved as mitigation for nitrogen deposition impacts, including the Valley Transportation Authority (for Highway 101 expansion) and the Silicon Valley Land Conservancy (for three gas-fired powerplants). A recent mitigation acquisition by the Santa Clara Valley Water District (for riparian impacts) raised the contiguous total above 800 acres. The Santa Clara County Open Space Authority manages much of this land under contract.

The new Tulare Hill Land Bank (Santa Clara County Parks) along with the existing Metcalf Energy Center Ecological Preserve (Silicon Valley Land Conservancy) and a PG&E Safe Harbor Agreement now protect almost all of Tulare Hill. The Coyote Valley Open Space Preserve (Santa Clara County Open Space Authority) protects one of the small islands west of the valley. Other previously protected serpentine grasslands in the region include Harvey Bear-Coyote Lake County Park, Calero County Park, Rancho San Vicente, Santa Teresa County Park, and Rancho Canada del Oro Open Space Preserve.

Proper stewardship maintains the rich biodiversity of these serpentine grasslands. Managed cattle grazing mitigates impacts of nitrogen deposition from upwind Silicon Valley sources, by reducing annual grasses cover and biomass. The Central Valley Project Conservation Program (CVPCP) is supporting reintroduction of grazing into Santa Teresa County Park. Weed management, especially of barb goatgrass, is ongoing in several mitigation projects. Thousands of Bay checkerspot butterflies were moved to Tulare Hill in 2013, and a population appears to have been established. In 2013, CVPCP funded projects for restoration of two of the listed plants (Metcalf Canyon Jewelflower and Tiburon Paintbrush).

The high nitrogen deposition in this region is a major nexus for the Santa Clara Valley Habitat Plan, a Habitat Conservation Plan/Natural Communities Conservation Plan to conserve 19 imperiled species in southern Santa Clara County through acquisition/easements on ~46,000 acres. The Habitat Plan is estimated to cost $665,000,000 over the 50-year permit period. After more than 10 years of planning, the plan was adopted by local elected officials, and the Implementation Agreement was signed in October 2013 giving birth to the Santa Clara Valley Habitat Agency.

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