"Sonoma Mountain is the prominent 14-mile-long range that separates Petaluma and the Highway 101 corridor from scenic Sonoma Valley. The prominent landform tops out at 2,463 feet and is among the highest points in Sonoma County. North Sonoma Mountain Regional Park and Open Space Preserve, opened to the public in 2014, is a stunning 820-acre parkland on the north slope of the mountain. The open space is located southeast of Santa Rosa between Rohnert Park and Sonoma Valley. The land lies adjacent to Jack London State Historic Park on its west side. Within the regional park are numerous creeks surrounded by dense forests of coast live oak, black oak, bigleaf maple, Pacific madrone, Douglas fir, bay laurel, and coast redwoods, with an understory of blackberry, toyon, and western poison oak. The open slopes are covered with chaparral and grasslands. A 4.25-mile trail climbs to the mountain summit. Atop the ridge, the trail seamlessly connects to Jack London State Historic Park via the Hayfields Trail near the summit. The trail gently winds through diverse landscapes, including dark shaded forests, broad meadows, and upland valleys. From the trail are sweeping views of Sonoma Valley, the Santa Rosa Plain, the coastal range to the Pacific Ocean, and the Mayacamas Mountains. The multi-use trail is open to hiking, biking, and equestrians. The North Sonoma Mountain Trail is part of the Bay Area Ridge Trail around the San Francisco Bay area. To date, about 340 miles of the Bay Area Ridge Trail are complete. This trail has added another vital link in the projected 550-mile loop."