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Friends of Trione-Annadel is the nonprofit dedicated to protecting the health of our treasured local state park, Trione-Annadel. Through donations from our community, we support the maintenance and development of its trails, structures, and open spaces - ensuring a healthy environment for wildlife and continued accessibility for the public.

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Friends of Trione-Annadel was created in September 2017 in response to increasing maintenance needs of a highly used recreational.

Trione-Annadel State Park has over 45 miles of official trails and hosts 12-13,000 people per month of all types - hikers, mountain bikers, runners, equestrians, and more.

To support the preservation and maintenance of this unique natural resource, Friends of Trione-Annadel was formed with the intent to protect park resources and deliver a high-quality visitor experience. Read more


With support from many generous donors, Friends of Trione-Annadel has funded numerous projects benefiting the park. Recent projects included the installation of 17 new Kiosks (donated by the Trione family) throughout the park, the completion of repairs to the dam at Lake Ilsanjo, and the purchase of fire fighting equipment and an all-terrain wheelchair to give visitors with disabilities the ability to access trails in the park.

Our goals for 2024 include supporting completion of approved trail work on Channel, Two Quarry, and Lawndale trails.

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Trione-Annadel State Park is situated at the northern edge of Sonoma Valley and is adjacent to Spring Lake Regional Park in the City of Santa Rosa. Within its 5,200 acres and 40+ miles of hiking, biking and equestrian trails, it offers many recreational and wildlife viewing activities.

Trione-Annadel State Park's interconnected trail system includes an 8.5 mile section of the Bay Area Ridge Trail. The park’s trails are a popular destination for runners, hikers, mountain bikers and equestrians. Read more

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