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Annadel State Park

Warren Richardson, Steve’s S Trails
To Lake Ilsanjo is 5 miles round trip with 500-foot elevation gain;
circling the lake adds an additional 2 miles

Thirty-five miles of hiking trail plus good black bass and bluegill fishing are the highlights of Annadel State Park. Tucked away in the heart of the park, Lake Ilsanjo, where the fish bite and hikers hike, is a pleasant destination for day hike. Bring meal worms to tempt the bluegill to bite, or purple plastic worms for the bass, or simply bring your own picnic and let the fish feed themselves.

The lake’s Spanish-sounding name does not date from the days of the ranchos and rancheros, as one might guess; it’s actually a composite formed from the first names of two former landowners, Ilsa and Joe Coney, who built the lake in 1956.

It was not the tranquil shores of Lake Ilsanjo, but the rocky hills around it that brought the first humans to the area. Pomo and Wappo gathered obsidian, using the shiny black rock to fashion knife blades, arrowheads and spearheads.

Settlers, too, came for the rocks. Basalt was quarried here at the turn of the century to build San Francisco; after the great 1906 earthquake, the rock was used to rebuild the city. Also quarried, for city streets, was cobblestone, though in no time such paving fell into disfavor with drivers of the new horseless carriages.

Once part of the 1837 Mexican land grant, Rancho Los Guilicos, the Annadel area was owned by a series of farmers and gentlemen ranchers. Annadel became a state park in 1971.

A favorite way to Lake Ilsanjo is via Warren Richardson Trail, a wide path that honors a prominent Sonoma County cattle rancher and avid horseman with a love for trails. Warren Richardson Trail winds through a cool forest and crosses an open meadow on the way to the lake. For a fun return trip, loop back on steep, fern- and fir-lined Steve’s S Trail.

Directions to trailhead: From Highway 101 in Santa Rosa, exit on Highway 12 (toward Sonoma) and follow it east through town. Turn right on Montgomery Drive, then right again on Channel Drive and follow it a mile into the park. The park office (where you’ll find water, maps for sale) is at the entrance; trailhead parking is a mile farther down the road.

The hike:
From the parking lot, join the trail leading south, which in no time at all delivers you to a dirt road—Warren Richardson Trail. You’ll pause to view an interpretive display about how the Indians used acorns, then spot Steve’s S Trail (your return route) on the right.

About 0.75 mile of easy walking from the trailhead brings you to a hairpin turn and a junction with Two Quarry Trail. Swing northwest on Warren Richardson Trail and begin ascending through a forest of redwoods and Douglas fir. Sword ferns seem to point the way uphill.

The dirt road turns south again, passes a junction with Louis Trail, then begins descending. You get your first glimpse of Lake Ilsanjo. Emerging from the woods, you cross a meadow to the lakeshore.

To circle the lake, continue on Warren Richardson Trail, then join Rough Go Trail and Middle Steve’s S Trail. Parts of the lakeshore are carpeted with blue-eyed grass.

Your return route joins Steve’s S Trail, which skirts the east end of the meadow as it begins to ascend. Topping a hill, the path joins up with the North Burma Trail for a brief descent; then Steve’s S Trail forks left and descends through a Douglas fir forest. A mile’s descent deposits you on Warren Richardson Trail, very close to where you began this hike.

© 2012 The Trailmaster, Inc.
From John McKinney’s
Day Hiker’s Guide to California’s State Parks
Trail descriptions and maps have been reproduced with the permission of the author.  To learn more about The Trailmaster and other related publications please visit their website at