Trione Annadel State Park

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Santa Rosa, CA
Trione Annadel State Park

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Discover the stunning rolling meadows, peaceful Lake Ilsanjo, and diverse wildlife.

Official account for Trione-Annadel State Park.
6201 Channel Drive, Santa Rosa, CA
The park offers 40+ miles of scenic trails for hiking, biking, and horseback riding.

10/09/2026

🎃 No tricks here—just trails and treats!

Join us at Trione-Annadel State Park for a spooky nighttime stroll along Channel Drive!

🔦 Explore the park with a blacklight and discover glowing fungi, plants, and other surprises hiding in the dark. Then head back to the Visitor Center for our spook-tacular costume contest and, for those over 21, a complimentary beverage from Old Caz B**r ! 👻

🏆 The top three costumes will win prizes, so bring your best spooky, silly, or creative look!

📅 Date: Saturday, October 24th, 2026
⏰ Time: 6:00 PM- 8:30 PM
📍 Meet at: Trione-Annadel Visitor Center

The route is easy, paved, and flat. Bring warm layers, water, a flashlight or headlamp, and sturdy, closed-toe shoes. Blacklights will be available to borrow while supplies last.

Registration is REQUIRED for all participants. Visit our Eventbrite link to register👇
https://www.eventbrite.com/e/blacklight-hike-with-old-caz-and-friends-of-trione-annadel-fota-tickets-2003218043092

📌Anyone under 21 must be accompanied by a parent or guardian.

Come explore the park after dark, show off your Halloween spirit, and raise a glass to our beloved trails!

Presented by -Annadel in partnership with B**r. Learn more at friendsoftrione-annadel.org

Image Descriptions:
1. A flyer with event information about an upcoming blacklight hike at Trione-Annadel. The background is the map of the park.
2. An image of a glowing millipede after shining a blacklight on it.
3. An image of a glowing plant after shining a blacklight on it.

09/30/2026

State Parks crews will be completing the maintenance work on Canyon Trail tomorrow, Thursday, October 1, from 7 AM–5 PM.

During this time, visitors should expect temporary delays and partial closures along the trail as crews and heavy equipment work in the area.

To help keep everyone safe and minimize delays, we recommend choosing an alternate route or avoiding the Canyon Trail during these hours.

🚧 If you do choose to visit the area, please follow all posted signs and directions from park staff.

Thank you for your patience while we work to maintain and care for the park!

Image Description: An image of a trail with green grass and blue skies in the background. Text overlay notifies viewers of the date, time, and impacts of upcoming trail work on Canyon Trail in Trione-Annadel State Park. There is an orange traffic sign in the right corner of the image that reads, "Road Work Ahead."

08/21/2026

On behalf of our friends over at the Sonoma Developmental Center Open Space (SDC):

Join us for a fun BioBlitz at a brand-new State Park property in celebration of California Biodiversity Day 2026! 🌱

🔍Discover the history of the Sonoma Developmental Center Open Space property and learn how to use the iNaturalist app to help us collect biodiversity data.

📌Meet at the intersection of Harney and Railroad in Eldridge, CA, at 10 AM, and we will walk together to the peak of Lake Suttonfield, where the activity will begin.

No RSVP is required for this FREE event!

The Suttonfield trail is an easy to moderate unpaved trail with light elevation changes and inconsistent shade.

💧Water, sturdy shoes, and hats are recommended. A smart device with the iNaturalist app already downloaded is recommended before arrival.

Join the iNaturalist project: https://www.inaturalist.org/projects/california-biodiversity-day-2026-sdc-open-space-bioblitz

#2026

Image Description: Flyer for the SDC Open Space 2026 BioBlitz on Saturday, Sept 12, 10AM-12:30PM at Harney & Railroad, Eldridge, CA. Features a scenic lake, a hand holding a smartphone, a QR code, and contact info: [email protected].

08/17/2026

ICYMI: We've added a beautiful new ramada and picnic area behind the Visitor Center! 🎉

We want to shout out our awesome contractors and maintenance staff for working so hard to get this project finished. 🥳🏆

(It's a great, new spot to rest in the shade and refuel for your adventure!) 🤩

Image Descriptions:
1. An image of a newly installed shaded picnic area behind the visitor center at Trione-Annadel. The image features three picnic tables, a ramada structure, and a trash receptacle.

2. This image features the same picnic area but is taken from a different angle, facing north.

08/14/2026

The 2026/27 school year is officially here, and we’re celebrating with the ultimate family perk: a FREE 4th Grade Pass! 🌲🚙

This pass gives your incoming fourth grader (and the whole family) unlimited, zero-cost entry to 54 incredible state parks for up to 13 months (from Aug. 1 to Aug. 31 of the following year)!

Where will you go first? Swipe to see the participating parks.

🌲 Walk among giants at Jedediah Smith Redwoods
🏖️ Cool off at Millerton Lake
🌵 Explore the wild desert landscapes of Anza-Borrego Desert

🎟️ Claim your free pass today: Head to the link in our bio 🔗
or visit [reservecalifornia.com/passes/Advancepasses]

#

Image Descriptions:
1. A group of students exploring a redwood forest. Trees and ferns are in the background.

2. A map of the state of California, with little yellow flags marking each one of the 54 state parks that accept the free 4th grade pass. There is a complete list of the 54 parks split up by region listed below the map.

07/05/2026

Beginning Monday, July 6, 2026, State Parks staff and contractors will be conducting maintenance on the Lake Ilsanjo dam, including work on the outlet pipe to help protect the lake's resources.

💧State Parks does not expect to lower the lake level during this project.

🚜 Heavy equipment and crews will be present from Monday to Thursday, 7 AM–5 PM, until the work is complete.

🚧Work/Staging Areas include:
-Warren Richardson/Louis Trl. Junction
-Lake Trail & Service Road
-Canyon Trail & Fire Road
-Along the Lake Ilsanjo Dam

⚠️During this time, expect temporary delays on the trails, and proceed with caution while recreating near the worksite. Please follow the directions of all posted signage.

📍Please note: State Parks may implement full trail closures at certain points during the project to ensure the safety of visitors.

➡️ Scroll right to see the planned work areas.

You can check the park’s website or social media for updates about potential trail closures in the project area.

❓Questions about the project can be directed to: [email protected]

Image Description(s):
1. Dam maintenance graphic over an image of the Lake Ilsanjo Dam announcing delays in the area starting July 6th, Monday through Thursday, 7:00 AM to 5:00 PM.
2. Map showing maintenance area near Lake Ilsanjo, with yellow stars marking the work zone and surrounding equipment staging areas in Trione-Annadel State Park.

07/02/2026

Wherever your Fourth of July adventures take you, a little preparation goes a long way. 🤝

Check out these safety tips and have a fun, safe holiday weekend! 🎆🎊

07/01/2026

Trails to Tomorrow is coming up! Make sure to mark it on your calendar and head to the link below to purchase tickets and learn more! 👇

Address

6201 Channel Drive
Santa Rosa, CA
95409

Telephone

+17075393911

Website

https://www.parks.ca.gov/?page_id=480

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