Briones Special Management Area

The Special Management Area is the same area as the Briones Pilot Project Zone. It is limited to a 1,600-acre area located in the Northeast corner of Briones Regional Park. The Special Management Area can be accessed from the Alhambra Creek staging area, Old Briones Road staging area, the park office entrance near Pine Tree Trail, and the Reliez Valley staging area. The northern boundary of the Special Management Area excludes the Orchard trail, first ¼ mile of the Pine Tree trail (from the Briones Park office entrance to the junction of the Toyon Canyon trail), and the Toyon Canyon Trail. This allows bikes or equestrians to use the Alhambra Creek and Orchard (Park Office) staging areas to access the rest of the park on restricted weekend days instead of having to go all the way to the Bear Creek entrance. See Briones Special Management Area Map.

The Briones Pilot Project was a 20 month pilot (from April 21, 2023 – December 17, 2024) that established specific rules limiting trail use within the Pilot Project Area and for two trail segments adjacent to the Pilot Project Area, such as hiking only, biking only, or biking/hiking only and direction of travel. On weekends, trail use within the Pilot Project Area alternated between bicycle and equestrian use based on even and odd calendar dates (see table). A key component of the Project was the restoration of illegally built “bootleg” trails to protect natural habitat for wildlife. Following the conclusion of the Briones Pilot Project in December, 2024 the Park District Board of Directors formalizes the specific trail designations and rules established during the Pilot Project and authorized the amendment of Attachment A of Ordinance 38 to include an additional 5.75 miles of trails within Briones Regional Park.

Over the last decade visitation to District parks has increased significantly. This rise in visitor numbers has been primarily due to increases in the population of our District (Alameda and Contra Costa County) but also in the Bay Area as a whole. The Covid-19 pandemic also boosted visitation significantly, especially on District trails. Another impact has been the significant growth in the popularity of mountain biking. The increased number of trail users overall coupled with the greater number of bikers has increased the potential for conflict between different types of trail users. Although the Park District is seeking to open new parks and provide more trails to reduce crowding on trails, the trail development process takes time.

BIKES ARE NOT ALLOWED TO ENTER THE SPECIAL MANAGEMENT AREA ON EVEN WEEKEND DAYS, but trails outside the area that are designated for bicycle use are still available to ride. Most of these are accessible from the Bear Creek entrance to the park, but the northern boundary of the Special Management Area allows for a bypass of the area using the Orchard trail, the first ¼ mile of the Pine Tree trail (from the Briones Park office entrance to the junction of the Toyon Canyon trail), and the Toyon Canyon Trail. This allows bikes or equestrians to use the Alhambra Creek and Orchard (Park Office) staging areas to bypass the area and access the rest of the park on restricted weekend days instead of having to go all the way to the Bear Creek entrance. The Special Management Area was specifically limited to allow for bike use in other areas of the park outside the Special Management Area on restricted use days. See Special Management Area Map.

Community volunteers play an important role in helping park staff monitor and maintain park trails. The Park District will provide volunteer opportunities and encourage more members of the trail user community to join in trail maintenance and habitat restoration activities. Volunteer projects will consist of a combination of restoration and improvement of trails within the Special Management Area. Sign up for Dig Days. 

All areas of Briones Regional Park shall be governed by trail and park use rules under Ordinance 38 seven days per week. Please be prepared to encounter trail crews, park district staff, and other trail users inside and outside of the Special Management Area and proceed with caution when passing workers and other park visitors. It is your responsibility to know the trail rules. View Ordinance 38.

Illegally built trails are constructed without consideration for the protection of threatened or endangered species, and sensitive plant communities and can disturb streambank stability and create erosion potential.
Some of the issues caused by illegally built trails are:

• Human presence in areas previously providing protection: Existing trail systems are designed to intentionally preserve certain areas of open space as intact habitats for sensitive plant and animal communities. Illegal trails fragment these areas of open space and bring human presence into these previously protected areas, disrupting wildlife activity like nesting eagles and spreading pathogens such as Sudden Oak Death and introducing invasive plant species.
• Erosion and threats to stream habitats including those of the California red-legged frog: The illegal trails in extremely steep terrain are causing substantial erosion into streams. The sediment from this erosion causes harm to wildlife that occupies stream habitats, such as the threatened California red-legged frog.
• Damage to the habitat of the state and federally threatened Alameda whipsnake: Some illegal trails are constructed in scrub/chaparral habitat which is a core habitat occupied by the state and federally threatened Alameda whipsnake. The trails have damaged habitat essential to this sensitive species as well as increased the likelihood that individual Alameda whipsnakes will be crushed by a bicycle.
• Maintenance, Safety Hazards, and Drainage Issues: Many non-sanctioned trails are not built to sustainable trail standards and can present maintenance, safety hazards, and drainage issues.
• Public Safety Concerns: Many of these trails have been created without the knowledge of park staff and public safety personnel. If a trail user requires emergency assistance, it can be difficult for public safety personnel/park staff to find them or get resources to them quickly since the trails are in unknown locations, have no official name, and do not exist on Park District Maps.

The following criteria were used to identify trail closures and restoration priorities: 

• Does the trail traverse high quality habitat for federally and/or state listed wildlife species, such as Alameda whipsnake?
• Is trail within line of sight of a known golden eagle nest?
• Does the trail cross streams and or occur within a stream corridor?
• Is there observable erosion occurring along the trail?
• Does the trail traverse a CDFW sensitive plant community? 
• Is the trail established or actively being constructed?

Based on these criteria, the following ecological and recreation benefits were accomplished:

• All bootleg trails within/adjacent to Alameda whipsnake core habitat either closed/restored or designated hiker only  
• Trails with most stream crossings and erosion closed/restored
• Trails within stream bed closed and restored or to be restored
• Trails within line-of-sight of golden eagle nest closed/restored
• Reduced habitat fragmentation
• A network of bootleg trails “opened” that provides various routes through the Special Management Area including terrain/trails valued by mountain bike community
• Scenic hiker only trails opened