Environmental Stewardship
Supporting Protected Butterflies
The threat to federally listed butterflies on San Bruno Mountain is real, as open grassland is being “taken over” by coyote brush and other native scrub, as well as invasive weeds.
To help maintain grassland acreage for the mountain’s four protected butterfly species, the San Bruno Mountain Habitat Conservation Plan (HCP) works with volunteers, nonprofits and contractors to remove scrub and invasive weeds on the mountain.
But it’s still not enough.
Our Committments to Environmental Stewardship
$1.8 million
Estimated initial contribution to San Bruno Mountain HCP.
57% Open Space
82 acres – more than half of the quarry property – will be set aside as protected open space.
#1 Ongoing Contributor
As the largest development (by square footage), the Quarry Innovation Center will be the #1 annual contributor of HCP Fees
As part of our commitment to environmental stewardship, the Quarry Innovation Center has pledged to protect 82 acres, about 57% of the quarry property, and make an initial payment of $1.8 million, in addition to ongoing annual payments, to fund active implementation of the San Bruno Mountain HCP.
The San Bruno Mountain HCP’s 2025-26 budget for vegetation management contracts and fuel reduction is about $270,000, about one-third of its total expenditures.
The Quarry Innovation Center’s initial and ongoing contributions to fund active implementation of the HCP have the potential to be transformative investments, managing for desired butterfly resources and reclaiming or expanding grassland acreage for protected butterflies through scrub control.
Maintaining Habitat for Protected Butterflies
San Bruno Mountain is home to four protected butterfly species: the mission blue, callippe silverspot, San Bruno Elfin and bay checkerspot.
The Quarry Innovation Center proposes to set aside 82 acres, or more than 57 percent, of the quarry property as protected open space, adding 46 acres to San Bruno Mountain Park and putting 36 acres under a conservation easement. The land proposed for conservation and open space has been found to have a much greater number of larval hostplants for protected species than the active quarry site.
These 82 acres will benefit from targeted restoration and/or vegetation management. They have the elements needed for suitable butterfly habitat, including nearby nectar resources, and could be managed to support one or more of the federally listed species.
Learn about the San Bruno Mountain HCP
The San Bruno Mountain HCP is administered by San Mateo County staff, reporting to the HCP Trustees, a group that includes the County Manager and the City Managers of Brisbane, Daly City and South San Francisco.
You can view HCP core documents, agendas and minutes from Trustee meetings and more on the HCP website by clicking the button below: