Hike to Pluto!

Do the Amazing PlanetWalk in Sugarloaf Ridge State Park

01.17.2019

Ever wanted to check out Mars? How about Jupiter, Neptune, and Pluto? All you’ve gotta do is hike in Sonoma Valley’s Sugarloaf Ridge State Park. The park’s super cool PlanetWalk is a marvelous, and marvelously quiet, hiking trail designed as a scale model of the solar system. On the route you’ll pass nine trail signs representing each of the planets in the solar system and providing a visual interpretation of the vast spatial relationships between planets and also their sizes in proportion to the sun, so large that a million Earths could fit inside.

PlanetWalk is about 2.2 miles (one-way) to the pinnacle orbit of (now demoted) Pluto. For a full fanfare of fantastic views, we recommend extending the route to encompass a 7.5-mile round-tripper straddling both Sonoma and Napa valleys. NOTE: This is an exposed hike, so do not do it on hot days; check the weather prior, and time your hike accordingly. Always bring plenty of water.

Start at the southeast corner in the parking lot of Sugarloaf’s Robert Ferguson Observatory. From the sign representing the Sun, quickly pass the inner planets and follow the Meadow Trail to Mars, Jupiter, and Saturn. At a bridge 1 mile in, pay homage to the iconic Heritage Maple nearing the end of its life; in its prime this was one of the area’s largest big-leaf maples.

Keep stoking your celestial senses as you climb Brushy Peaks Trail through a forest of bay trees and second-growth redwoods, with Uranus appearing, too (just sayin’!), as well as Neptune (a good turnaround point with very satisfying views, best for those wanting to keep the hike as a shorter, easier 3.2 mile out-and-back hike), and then Pluto. Trees burned and bruised by the fires loom stark and charred, but lush green new growth bursting around the trunks of injured trees is a testament to nature’s resiliency. Brushy Peak’s summit is simply breathtaking—a panorama spanning both the soft rolling vineyards and dramatic foothills of Napa and Sonoma. On clear days you’ll see as far as Mount Diablo to the southeast and Mount Tam to the southwest. Round out the hike by connecting the following trails: Red Mountain, Headwaters, Vista, Bald Mountain and Lower Bald Mountain. It's one big counter-clockwise loop.

BONUS STAR PARTY: Sugarloaf Ridge State Park is home to the largest observatory in the western United States: Robert Ferguson Observatory. On select nights it opens to the public for night and solar viewing. NOTE: Check ahead for weather as this may be weather permitting. There is a parking fee. (Daytime solar observing is no cost.)

{SEPTEMBER 2024 NOTE}: Road work in the park is scheduled during weekdays starting September 9 and lasting until September 19. Weekday mornings Adobe Canyon Rd within the park will be closed from mornings to early afternoons. Weekends should not be affected. 

No dogs (except in the campground). More info and maps.

Trending Stories NorCal

View all Stories
  1. Perles Beach Angel Island San Francisco Bay

    Secret Beach

    A hidden beach and a killer view? Those are hard to come by, but that’s exactly what you’ll get at Perles Beach on Angel Island. Bike or hike to this beautiful pocket cove.

    View

  2. Cinematic Sonoma

    Longer days. Golden light. Wildflowers in bloom. It’s the perfect moment to plan your spring escape to Sonoma for the Sonoma International Film Festival, March 25–29. No fuss. No sprawl. Just films, friends, fresh air, and that unmistakable Sonoma glow.

    View
  3. Hike Pescadero Marsh Natural Preserve

    Mellow in the Marsh

    Beach, birds, ice plant popping purple flowers: That’s a hiking slam dunk! Hike about 2 miles at Pescadero Marsh Natural Preserve using their easy to navigate (well-signed) Sequoia Audubon Trail.

    View
  4. A man is looking through his binoculars at sunrise at the Bayland Nature Preserve in Palo Alto

    Baylands Bird & Art Loop

    Combine an outdoor art walk and wildlife sightings at the Baylands Nature Preserve in Palo Alto. This 5-mile loop through Byxbee Park and the Emily Renzel Wetlands features striking installations by artists Peter Richards and Michael Oppenheimer—where the landscape itself becomes part of the canvas.

    View

Trending Stories SoCal

View all Stories

  1. Tree Town

    Home to an estimated 21,000 trees and 100 acres of parkland, South Pasadena has earned its nickname: the City of Trees. This 2.5-mile neighborhood walk lets you experience its leafy canopy up close, winding through charming streets and three of the city’s beloved parks.

    View

  2. A Better Way to Baldwin

    The Baldwin Hills Scenic Overlook in Culver City is one of West L.A.’s most popular hiking spots, but most visitors miss the bigger picture. This 3.5-mile out-and-back along a section of the Park to Playa Trail offers a fuller experience of this gorgeous nature park with sweeping urban views and a few artistic surprises along the way.

    View
  3. Sponsored

    Warm Up to Winter in Reno Tahoe

    2026 is just getting started, but there’s one place already rising to the top as the best for adventure and relaxation: Reno Tahoe. The awe—and ahhhs—begin as soon as you arrive. G

    View
  4. A woman standing at the pond's edge at Ernest B Debs Regional Park in Los Angeles. Trees are making reflections on the pond.

    Urban Oasis Loop

    Home to the city’s Audubon Center, Ernest E. Debs' 282-acre park features a robust network of hiking trails and surprising wildlife diversity. More than 140 bird species have been spotted here. Birdwatcher or not, this 2.5-mile route makes for a gorgeous outing.

    View