Are dogs allowed on Fairfield Osborn Preserve South Loop?

Yes, dogs are allowed on Fairfield Osborn Preserve South Loop but must be kept on a leash at all times. Pack out waste and respect wildlife.

Do I need a permit to hike Fairfield Osborn Preserve South Loop?

Yes, Fairfield Osborn Preserve South Loop requires a permit. Sonoma State preserve; open to the public by reservation or guided tour only. Apply through the issuing agency at https://cei.sonoma.edu/visit-preserves-gardens/reservations before your visit — many systems run lotteries with fixed application windows.

How difficult is Fairfield Osborn Preserve South Loop?

Fairfield Osborn Preserve South Loop is rated easy. It is 1.9 miles long with 430 feet of elevation gain. Difficulty ratings reflect a combination of distance, elevation gain, and terrain — your experience will depend on your fitness level and trail conditions.

Status unknown — verify before visiting

We don't have current condition data for this trail. Check with the land manager before you go.

See California trail conditions

EasyLoop

California

Fairfield Osborn Preserve South Loop

Penngrove, California

1.9 mi

Distance

430 ft

Elev. Gain

11m

Est. Time

Loop

Route Type

Easy

Difficulty

About This Trail

Imported description

Visitors must make a reservation to visit this reserve. The top of Sonoma Mountain overlook the Valley of the Moon to the north and the Santa Rosa Plain to the west.

Trail Conditions

Unknown

We have no current condition data for this trail. Check with the operator before you go, and submit a report below if you've been recently.

Reservation required: Sonoma State University Center for Environmental Inquiry preserve, open to the public by reservation/guided hike only.

No recent condition reports. Be the first to share what you see on the trail.

Elevation Profile

Min:459 ft

Max:521 ft

131 ft

Trail Details

Route Type: Loop
Surface: Dirt

Permit required

Apply through the issuing agency. Many systems run seasonal lotteries or fixed application windows — confirm current dates on the agency page.

Sonoma State preserve; open to the public by reservation or guided tour only.

Get permit

Official sources & verification

Verify before you go

Reserve or permit

Apply for permit
Required permit application for this trail. Many systems run seasonal lotteries or fixed application windows — confirm current dates here.

Reviews

No reviews yet

Be the first to share your experience and help others plan their visit.

Legacy import — verify before navigating

Path geometry came from our pre-launch legacy database. Routes have not yet been re-verified against the operator and may differ from the actual trail.