Two people on mountain bikes wearing helmets overlook the valley below
Trione-Annadel State Park

Trione-Annadel State Park: A Wild Paradise

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Get away from it all in Trione-Annadel State Park, which boasts 5,092 pristine and largely undeveloped acres on the eastern edge of Santa Rosa, in the heart of Sonoma County.

And - thanks to more than 40 miles of multi-use trails geared to hikers, mountain bikers, and horseback riders - you can explore much of this wonderful place on your own. There's lots to see.

Trione-Annadel's hilly terrain supports seasonal streams, meadows, redwoods, grasslands, a 26-acre lake, dense chaparral, volcanic rock formations, and what many biologists consider to be a prime example of undisturbed northern oak woodlands.

This wide variety of ecosystems creates welcoming habitat for lots of wildlife, including the commonly seen black-tailed deer, western gray squirrel, skunk, opossum, coyote and raccoon, as well as the more rarely-seen bobcat and mountain lion.

Man-made Lake Ilsanjo holds bluegill, black bass, and largemouth bass. And in the park's Ledson marsh, you might glimpse a red-legged frog, which is a threatened species.

Birds commonly sighted in Annadel include the western scrub jay, Steller's jay, wild turkey, wood duck, acorn and pileated woodpeckers, pygmy owls, black phoebe, and dark-eyed junco.

trione annadel state park

Wildflowers bloom as early as January and run into September, but the really magnificent displays tend to occur in spring - particularly in April and May. You'll find lupines, blue-eyed grass, popcorn flower, poppies, buttercups, bluedicks, shooting stars, iris, zigadene, hound's tongue, linanthus, and more. Maybe you'll even spot a fairy slipper orchid.

Plan your hiking visit by downloading the park brochure with trail map. Most of the trails connect, allowing you to design a hike to your liking. The elevation low-to-high chart can help you hone that hike to perfection.

Channel Trail, which only rises from 344 to 390 feet, is relatively flat - perfect for a hiking newbie or a low-energy day. Lawndale, rising to 1,236 feet from a mere 482, will provide a challenge for more experienced hikers.

Other ways to enjoy Trione-Annadel:

  • Bring a picnic. Tables are scattered about the Park, offering a range of lovely views (some tables are arranged around the lake).
  • Go fishing at Lake Ilsanjo. Anglers more than 16 years old must carry a California fishing license.
  • Check out Wymore Quarry. Follow Cobblestone Trail to Wymore Quarry where, at one time, cobblestones were taken away on a gravity-powered, narrow-gauge railway. In the late 19th century and into the early 1920s, cobblestones were quarried here for construction projects in San Francisco, both before and after the 1906 earthquake.
  • Use accessible tables. The quarry lot also contains an accessible portable restroom and one parking spot designated as accessible. 

Feeling hungry or thirsty after your excursion? Venture a little further into Sonoma Valley along scenic Highway 12 and visit other popular wineries on the way, like Kunde Family Winery, St. Francis Winery & Vineyards, Chateau St. Jean, Ledson Winery & Vineyards, or VJB Vineyards, Cellars & Marketplace.

Next, catch your breath beneath the shade trees in the eight-acre Sonoma Plaza (the largest town center in California), then tour the surrounding National Historic Landmark adobe buildings designed in 1834 by the Mexican Governor Mariano Vallejo.

Lunch is calling now, and the longtime classic, French-country the girl & the fig on the square is a delight, for seasonal plates like duck egg ravioli with spring mushrooms, onion crema, green garlic, spring peas and baby carrots sprinkled in smoked paprika.

Find more info about parks, things to do, and hotels & lodging in Sonoma County.

Written by Sonoma Insider Suzie Rodriguez.