Welcome to Trione-Annadel State Park

Trione-Annadel State Park is located on the eastern edge of Santa Rosa in Sonoma County, California. The park reflects a rich mix of natural beauty and human history. Since time immemorial, the Wappo and Southern Pomo lived near here, thriving in the area’s oak woodlands, grasslands, and volcanic hills. They managed the land with deep care and continue their stewardship of the area's rich resources today. 

With the arrival of Europeans, cattle ranching and farming gradually replaced the native pattern of hunting and gathering. By 1837, the area had become part of the Los Guilicos Rancho, a Mexican land grant covering about 19,000 acres. In the late 1800s and early 1900s, sheep and cattle grazing gave way to basalt quarrying. Workers extracted volcanic rock to make cobblestones, which were shipped across the Bay Area to pave the streets of San Francisco and other growing cities. Visitors can still see signs of this industrial past, including old quarry pits and stone walls throughout the park.

The land that would eventually become the park, passed through many hands, including those of Joe Coney, who turned the property into a hunting and fishing retreat. He stocked the property with game birds and filled a man-made lake (Lake Ilsanjo) with black bass and other sportfish. When his fortunes began to diminsh in the 1960's, he decided to sell the ranch.

By the 1960s, the land faced the threat of development. Thankfully, local residents and conservationists stepped in to protect it. Their efforts led to the creation of Annadel State Park in 1971. In 2016, it was renamed Trione-Annadel State Park to honor the Trione family, who played a key role in preserving open space in Sonoma County.

Today, the park spans more than 5,000 acres and features over 45 miles of trails. It continues to be a cherished space for hiking, biking, horseback riding, and enjoying nature—serving both the local community and the region’s wildlife.

WEATHER 

Spring and summer temperatures are warm, with average highs in the 80s and 90s. Fall and winter can be cool, with temperatures in the 50s. Rainfall averages about 30 inches a year, most of it during the winter and early spring. Fog and snow are rare. 

Park Information

COLLECTING or DESTROYING anything in the park, including mushrooms, is prohibited. All natural and cultural park resources (rocks, flowers, wood, animals) are protected by law and must not be disturbed or removed.  

FEES – There is a vehicle day-use fee. Regular sized autos are $8. Cash payment or self-registration are availableat the Visitor Center on Channel Drive. There are many annual park passes available to cover the vehicle day use fee. Check here for a list of available California State Park Passes. 

DOGS are allowed in paved areas such as the Visitor Center parking lot area and along Channel Drive. Dogs must be on leash at all times. Dogs are not allowed on any trails or in backcountry areas.  

HORSES are allowed on all designated multi-usetrails/fire roads.Horses are not permitted on any pedestrian-only trails. Horse trailer parking is available at the Warren Richardson parking area near the end of Channel Drive. The staging area is complete with a horse-watering trough and a mounting ramp for those who may need it. There is also horse trailer parking, and a staging area located in Spring Lake Regional Park, which provides access to Trione-Annadel SP via the Canyon Trail.  

BICYCLES are allowed on all designated multi-use trails/fire roads. Bikes are not permitted on any pedestrian-only trails.  

E-BIKES Electric-Assist or “E-bikes” are considered motorized vehicles and are not allowed in the park. 

MOTOR vehicles are only permitted on the entrance road and designated parking areas within the park. 

FIRES, camp stoves, and barbecues are not permitted in the park. 

STAY on trails. Off-trail riding and hiking is not permitted.  

DRONES are not allowed in the park. To protect wildlife and cultural resources, and for the safety and welfare of visitors and staff, Model Aircraft (“drones”)/Unmanned Aircraft Systems (UAS)/Glider Use is not allowed in the park per Bay Area District Order No. 660-16-036.  

CAMPING is not permitted within Trione-Annadel State Park. Check out these nearby parks that offer camping facilities: 

• Sugarloaf Ridge State Park: Located approximately 12 miles east, offering traditional camping experiences. Reserve California - Search Results 

• Spring Lake Regional Park: Close to Annadel, providing a variety of outdoor activities along with a campground. Reservations | Sonoma County Regional Parks 

PROFESSIONAL/COMMERCIAL PHOTOGRAPHY AND FILMING requires a permit through the California Film Commission. For more information, please visit their website.  

ACCESSIBILITY 

The park provides accessible facilities, including picnic tables and restrooms. Additionally, a GRIT Freedom Chair: Spartan(insert link) is available for public use (inquire at the Visitor Center), allowing individuals with mobility impairments to navigate uneven terrain. There is also an accessible mounting ramp located in the horse staging area at the Warren Richardson Parking Lot.  

Some of the park’s wheelchair-accessible features include: 

• Channel Drive/Channel Trail  

• Visitor Center 

• Picnic Areas at Warren Richardson Parking Lot 

Visitors with disabilities who need assistance can contact the Visitor Center at:(707) 539-3911.