Directions to Northern California’s most active Public Observatory

From Highway 12 east of Santa Rosa, turn on Adobe Canyon Road toward Sugarloaf Ridge State Park. Follow the road up the canyon. From the Park’s entrance kiosk, proceed straight up the road, following the signs to the observatory. Please drive slowly—hikers and animals abound!

Just past the horse corrals, you will come to a green gate. Do not drive past the gate, even if it’s open. Park in the gravel area between the corrals and the green gate, then walk past the gate up the road a short distance to the observatory.

What to expect
A typical Public Observing Night is staffed by volunteers who run the observatory’s three main telescopes, operate smaller scopes in front of the observatory, provide education talks on astronomical topics in the classroom, help to park cars, and assist visitors move about the observatory in the dark. Visitors are encouraged to ask questions about astronomy, cosmology, telescopes, and the observatory itself. Alcohol is prohibited on Observatory grounds.

The Observatory is not open to the public except for scheduled events.

Night Viewing Times
Our start times are listed on the Star Parties page. We keep the observatory open as long as there are visitors, but you must arrive within 3 hours after start time to ensure that we remain open for you.

About Night Vision
Why do we use red light around the Observatory? It takes about 20-30 minutes for our eyes to adapt to the dark, and we want to see all we can through the telescopes! Red light interferes the least, but any light has an effect. We provide red cellophane covers for your flashlights, but please keep them pointed away from people, preferably at the ground. See our Star Parties page for more details.

Access for Visitors with Disabilities
The Observatory building is accessible with ramps. Restrooms are accessible. The classroom presentation and observing with both the 40″ telescope and the 14″ digital telescope are accessible. Other telescopes must be used while standing. When necessary, we can help you park your vehicle in a designated space near the building.

Please inform the parking attendants if you require this service. Accessibility stickers are hard to see in the dark!

logo for Museums for All

Museums for All

RFO is a proud participant in the Museums for All initiative, a collaboration with the Institute of Museum and Library Services to offer access to the observatory with free admission to our public star parties. Guests with an EBT card can present it at the entrance for free admission up to four guests (two adults, two children), including the guest. Parking fees for attending the public star party will also be waived.

Browse our Store
The Observatory has a retail counter inside the building’s main entrance that offers tools for observing such as planispheres, red flashlights, foot and hand warmers, binoculars, guides and more.

PlanetWalk is a scale model of the solar system designed to fit within the boundaries of Sugarloaf Ridge State Park. It’s a 4-1/2 mile round trip hike to Pluto and back, and gives you a physical appreciation of the distances between planets. Details

Sugarloaf Ridge State Park
For more information about hiking trails and Park amenities, visit the Sugarloaf Park website.

Sugarloaf Ridge State Park Air Quality

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