Exploring Sonoma’s Ancient Volcanic Landscape: A Hike at the Keen Property

Join Sonoma Ecology Center and Sonoma County Ag + Open Space for a rare opportunity to explore the privately protected Keen Property, a remarkable conservation easement tucked into the hills above Sonoma. While vineyards and oak woodlands define much of Sonoma Valley today, this landscape reveals an older story—one shaped by ancient volcanic activity that created dramatic rock outcrops, rugged ridges, and sweeping views across the valley.

Our destination is a beautiful exposure of the Sonoma Volcanics near the top of the ridge, where we’ll pause to take in the geology and the surrounding landscape. Along the way, you’ll learn about the history of the property, its role in protecting the headwaters of Agua Caliente Creek, and the importance of conservation easements in preserving special places like this for future generations. This hike takes place on entirely private land that is normally closed to the public.

DETAILS:

—Meeting Location: We’ll meet at the Field of Dreams Parking Lot (next to the Sonoma Police Department) at 151First Street West, Sonoma, 95476. We will meet at 9:00 am and caravan a short distance to the property’s entrance.
— Difficulty: This is a moderate to strenuous hike intended for experienced hikers. Although some of the route follows ranch roads, much of the hike is on uneven terrain without an established trail. Participants should be comfortable hiking on rocky terrain, moderate slopes, and off-trail surfaces. Trekking poles encouraged!
— Bring: sturdy hiking shoes suitable for uneven terrain; plenty of water (minimum 64 oz recommended); sun protection, long pants and layered clothing; lunch and trail snacks.
— Be aware of potential poison oak and ticks.

This outing is FREE to attend thanks to the voters of Sonoma County, who fund the work of Sonoma County Ag + Open Space with a quarter-cent sales tax.

Photo by Austin Noble