Trione-Annadel State Park is located in central Sonoma County, just east of the county seat of Santa Rosa. At over 5,500 acres, it sits near the northern end of the world famous wine growing area of Sonoma Valley. The land slopes downward towards the north from the Bennett Mountain peak in the Sonoma Mountains. The main entrance to the park is typically reached by turning onto Los Alamos off of Highway 12.
A view from the Warren Richardson Trail looking over the varied terrain at Trione-Annadel.
The Southern Pomo Indians lived in the area and the park was an important source for obsidian rock which could be used to make knives and arrow points. When hiking on some of the trails keep an eye open for the black shiny flecks of obsidian that sparkle like broken glass.
Coppertone leads the way towards Lake Ilsanjo.
The park eventually became part of the 19,000 acre Los Guilicos Rancho in the 1830's as cattle ranching and farming became more common. I addition to obsidian, the rocky slopes also yielded material used for cobblestones used to build San Francisco and Sacramento. Some of the remnants of those quarries can be seen today. The state of California acquired the property in 1971 and it became a park in 1974.
Trione-Annadel was and is the site of some aggressive forest management designed to maintain the historic oak woodlands nature of the area. Over the years many Douglas Fir trees have moved into the area, taking advantage of the lack of periodic fire that would naturally curtail their propagation. CalFire has "girdled" a number of the Firs to kill them off, which explains the strangely large number of dead trees or snags one can still find around the park.
Until 2016, the park was known as Annadel State Park. Following some research about the park's founding the Santa Rosa City Council successfully petitioned to have Henry Trione's name added to the park's moniker given his extensive efforts to make the park a reality. Many locals continue to refer to the park as simply Annadel and even the park's official brochures continue to sport the shorter name.
A segment of the Rough Go Trail at Trione-Annadel.
Despite having some nice hiking trails the most common visitor to Trione-Annadel seems to be mountain bikers. As one typically finds elsewhere, the vast majority and cyclists and hikers are courteous to one another and there are few issues. But given the differing speeds with which each group traverses the terrain it's important to be on your guard and ready to move to one side of the trail or the other.
Steve's "S" Trail
A view of False Lake Meadow from the trail.
near the main trailhead is the sole hikers only trail in the park and one of the more enjoyable segments. The tree cover here is complete with Douglas Firs and California Bay Trees overhead and ferns below. The trail is also a prime location to spot glassy obsidian on the trail.
The park extends to the north from the peak of Bennett Mountain. Though there are some steep pitches to be found here and there (such as on the aptly named Rough-Go Trail), much of the terrain consists of gently rolling slopes of moderate difficulty.
A view of Santa Rosa from Wymore Quarry.
Tree cover is mixed with some fully shaded and cool stands of trees interspersed with open, sunny and warmer grassy meadows. Among the trees to be found in the park are numerous varieties of Oaks, Big Leaf Maple, California Bay, Redwood and Douglas Fir.
Just as tree cover can vary greatly from segment to segment, so can the surface of the trail. For example, the Two Quarry Trail is very rocky. The South Burma Trail, which parallels it just a bit uphill has a surface that consists of largely packed dirt and is often dusty with a few boulders sprinkled about.
Coppertone walks on one of the many shaded trails in the park.
Trail junctions are well marked with wooden posts indicating what each segment is named and the number of rogue trails is thankfully small. With a fine trail map available at the main entrance gate there is little chance you'd get lost in Trione-Annadel.
A few spots in the park provide fantastic views into or out of the park. The site of the Wymore Quarry along Cobblestone Trail looks out over the growing expanse of Santa Rosa. The main fire road thoroughfare of the Warren Richardson Trail has a spot that provides a wide view over the park including Lake Ilsanjo and False Lake Meadow.
Lake Insanjo lies at the heart of the park and is the natural destination for many visitors. Numerous picnic benches around the perimeter of the lake provide spots for a meal or a snack before heading back out.