Las Trampas Wilderness Regional Preserve

Southern Las Trampas Land Use Plan Amendment (LUPA)


LUPA Key Goals

  • Open up landbank properties within the 756-acre project area.
  • Provide 3 park access points, including a 25-car staging area along Bollinger Canyon Road and 2 walk-in entrances.
  • Provides 4 miles of new multi-use trails.
  • Connect San Ramon and Danville to Las Trampas.
  • Close gaps in Calaveras Ridge Trail.

Site Description

The project is located in south-central Contra Costa County, on the western periphery of the San Ramon Valley within the City of San Ramon, Town of Danville, and unincorporated areas. The 756-acre project area consists of the former Peters Ranch, Chen, Elworthy, Podva properties and the Faria open space that will be coming to the Park District.

This project identifies opportunities to open up landbank properties for public access, close gaps along the Calaveras Ridge Regional Trail, and open up additional trails and access points to the public for hiking, bicycling, and equestrian activities. What is currently open for public access is a 12-car parking lot, a half-mile trail connection to Calaveras Ridge Trail, and a segment of the Calaveras Ridge Trail.

Native oak on the Peters Ranch
Native oak on the Peters Ranch property in spring 2017, EBRPD
Staff collecting residual dry matter sample in summer
Staff collecting residual dry matter sample in summer 2019, EBRPD
Mount Diablo seen from the Elworthy property in spring 2017
Mount Diablo seen from the Elworthy property in spring 2017, EBRPD


The project area is situated within a territory that was occupied by the Bay Miwok. The Bay Miwok were comprised of tribelets with lineages named for specific locations within the area they permanently occupied. The Tatcan tribelet lived in the project area in addition to Bollinger, Sycamore, and Green Valley Creeks, the western part of Mount Diablo and most of the Las Trampas Ridge.

The favorable environment of the project area, coupled with the abundance of natural resources, allowed the Bay Miwok peoples to be successful hunter/gatherers, and allowed them to establish village sites next to streams and creeks with seasonally occupied sites also located in the foothills of Mount Diablo. For the native people of east Contra Costa County, the mountain now called Mount Diablo, as well as the surrounding landscape, was sacred. Groups from distant places, such as the Sierra Nevada, revered the mountain as a place to pray and hold ceremonies, and the mountain figures prominently in several world creation myths.

The San Ramon Valley that includes present-day Town of Danville and San Ramon was used by Mission San Jose during the Spanish period (1772 to 1821) to graze sheep and cattle when the Spanish began to colonize the region and convert the Native population to Catholicism.

After Mexico gained independence from Spain in 1821, the San Ramon Valley was broken up into two large land grants, both called Rancho San Ramon.

In 1957, Bollinger Canyon Road (named after Joshua Bollinger who was the first European to settle in Bollinger Canyon) was paved by the U.S. Army to facilitate construction of the San Francisco Defense Area Site SF-25, a Nike surface-to-air guided missile system that operated from 1955 to 1959. The site was later used by the U.S. Air Force and then the California Army National Guard as a radio relay site until 1966.

Residential development was accelerated by the completion of Interstate 680 in 1965, and a severe drought in the 1970s, which put development pressure on local ranchers and farmers as grass and water for cattle diminished. As a result, many of the Valley’s ranches established in the nineteenth century were sold and developed into large subdivisions and business parks that encroached on the Valley’s walnut and pear orchards.

Bishop Ranch Pear Label
Bishop Ranch Pear Label / San Ramon Valley Historical Society

The Park District acquired the properties within the project area for natural resource protection and to provide recreation opportunities. Acquisition of the Peters Ranch property came in 1983 as a condition of a residential development project, as did the Elworthy property in 2015, and the Podva property in 2018. The Park District purchased the Chen property in 2007 to ensure protection of the open space from further development. The Park District expects to acquire the Faria property in 2023.

The Southern Las Trampas Land Use Plan Amendment will formally incorporate the landbank properties (Peters Ranch and Chen) and newly acquired properties (Elworthy, Podva, and Faria in 2023) into Las Trampas.


Ranching on Peters Ranch in 1934 / California Pioneers of Santa Clara County

Annual round ups and brandings were an essential part of raising cattle within the project area. Footage of life on the former Peters Ranch property also depict the San Ramon Valley with walnut orchards before the transformation to residential development.



The East Bay Regional Park District Acquisition, Stewardship and Development Division has completed a draft Land Use Plan Amendment (LUPA) and a Draft Environmental Impact Report (DEIR) for Southern Las Trampas Wilderness Regional Preserve (Las Trampas). The LUPA and DEIR are now available for public review and comment. The comment period initiated on October 31, 2022  and the 45-day review period will conclude on December 14, 2022.

The LUPA describes the existing conditions in the 756-acre project area and provides recommendations for future improvements. Project recommendations include: 1) opening landbank properties for public access, 2) providing approximately 4 miles of trails for public recreation, 3) providing public access points, including a 25-car staging area and 2 walk-in entrances, and 4) designating special resource protection areas for resource protection.

The DEIR addresses the potential physical and environmental effects for each of the environmental topics outlined in the California Environmental Quality Act (CEQA) for the recommendations provided in the LUPA. Due to the time limits mandated by State law, comments must be received no later than 5:00 p.m. on December 14, 2022. Please send written comments to Kim Thai, Senior Planner, via mail to: East Bay Regional Park District, ATTN: Kim Thai, Senior Planner, 2950 Peralta Oaks Ct., Oakland, California 94605-0381or via e-mail to:

The Park District will present the proposed LUPA recommendations to the Park District Board Executive Committee on November 10, 2022 and the Park District Park Advisory Committee on November 28, 2022. The Park Advisory Committee meeting will also serve as the public hearing for the DEIR.

Following the close of the Draft EIR comment period and preparation of a Final Environmental Impact Report (FEIR), the Park District’s Board of Directors will hold a meeting to consider certification of the EIR, adoption of findings, and project approval. A separate notice of this meeting will be provided to those who comment on the DEIR and posted on the Park District’s website when the date is determined. Board meetings are held at 2950 Peralta Oaks Court, Oakland, CA.

To view the Notice of Availability, the LUPA, the DEIR, and the DEIR Technical Appendices, as well as documentation of the public process leading up to the publication of these documents, please refer to the downloads below.


Project Resources

Project Materials

California Environmental Quality Act

Community Events and Public Hearings


Please contact Kim Thai, Senior Planner, at, or at (510) 544-2320 to be added to the project mailing list.