Save Mount Diablo Spearheads Remarkable Win for Contra Costa County

On June 2, 2026, Contra Costa County voters chose to protect open space and renew the Urban Limit Line by voting yes on Measure A! We won 70 percent of the vote in a remarkable landslide victory.

Save Mount Diablo led the effort to pass Measure A, which allows for continued open space and wildlife habitat protection, as well as good land use planning.

Measure A Renews the Urban Limit Line through 2051, a Huge Win for County Residents!

• Urban-style development can’t occur outside the line, so development threats to open space and agriculture are reduced.
• Development is focused away from areas that are designated Very High Fire Hazard Severity, keeping communities safe.
• Sensible planning is focused in areas with less car dependence, which means less traffic and less carbon pollution.
• Affordable housing can be concentrated around jobs and transit centers, not on the far edges of cities.
• Agencies will continue to receive local street maintenance funds through adopting the Urban Limit Line. For Contra Costa County, these funds add up to about $2 million a year to maintain our communities.

Measure A’s landslide victory sends a clear message to residents, developers, and decision makers alike: our communities want sensible development focused in areas that

• are less car dependent,
• have less wildfire risk, and
• have affordable housing closer to where people work and transit.

This is why Save Mount Diablo supported yes on Measure A and led the campaign to get it passed!

Our Landslide Victory Would Not Have Been Possible Without Support

Twelve different organizations, including pro-business and pro-housing groups, endorsed Yes on A:

• Mount Diablo Bird Alliance
• Greenbelt Alliance
• 350 Bay Area Action
• 350 Contra Costa Action
• East Bay Leadership Council
• East Bay for Everyone
• East Bay Times
• Golden Gate Bird Alliance
• League of Women Voters of Diablo Valley
• Sunflower Alliance
• The Nature Conservancy

The support of these organizations, as well as countless residents, made our remarkable victory possible.

With their support, we led an immensely successful campaign to renew the Urban Limit Line and protect our communities for decades to come.