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Petaluma Wetlands: Shollenberger Park, Alman Marsh, Ellis Creek

The Petaluma wetlands complex encompasses some 500 acres of tidal salt marshes and freshwater marshes, and has more than 7 miles of contiguous public trails that connect Alman Marsh, Shollenberger Park, and Ellis Creek. The wetlands are a birder's paradise; more than 225 species of birds have been identified here. On a clear day you can see Mt. Diablo to the south; to the east lies Sonoma Mountain, a long-dormant volcano.

Shollenberger Park is tucked inside an industrial park on the banks of the Petaluma River. A 2-mile loop trail circles the park; a 1-mile extension to the north leads through Alman Marsh to the Petaluma Marina. At the park’s northeast end you can connect to a 3-mile network of trails circling the polishing ponds at the Ellis Creek water recycling facility. To the west, a portion of the trail system parallels the Petaluma River; beyond it are hills clustered with native oaks.

Trail/Pathway Details

Shollenberger Loop Trail

Trailhead: Parking lot at Cader Ln.

Length: 1-2 total miles

Typical Width: 4 ft. & above

Typical Grade: Level

Terrain: Firm

At the start of the loop, if you follow the trail to the right, a paved section travels parallel to the dirt and gravel trail for almost .75 miles.


The 2-mile crushed gravel Shollenberger Loop Trail (a section at the beginning is paved) encircles city-owned dredge-spoil ponds that hold silt that has been dredged from the nearby Petaluma River. Pick up a self-guided tour brochure at the trail’s entrance to learn about the wetlands and their history (a curb blocks full access to the brochures). Nature did not disappoint on my visit: I saw swallows swooping up mud to make nests, northern harrier hawks searching for food, and two king snakes and three western pond turtles crossed the path. My companion reveled in finding swallowtail butterfly larvae on the fennel plants lining parts of the trail. Trail users include mothers with strollers, business people on lunch break, joggers, and birders.

I followed the loop trail in a counter-clockwise direction, staying on a paved trail that parallels the gravel trail for .75 miles before the two merge, then continued on gravel the rest of the way. At the start, you briefly parallel Adobe Creek—the bushes along the creek were alive with birdsong on my visit—before reaching the turn-off for the 1-mile Alman Marsh Trail. Shortly after the trail curves south and follows the Petaluma River you come to a viewing platform, but views of a gravel factory and some abandoned buildings didn’t entice me to linger. Since the wind was picking up––a common occurrence here––I turned back where the asphalt ended instead of finishing the loop. Had I continued, I could have extended my trip several miles by following the connector trail to the Ellis Creek water recycling facility ponds at the northeast corner of the loop.

Alman Marsh Trail

Trailhead: Foot of Marina Ave. and at Shollenberger Park

Length: 1-2 total miles

Typical Width: 30 in. to 4 ft.

The trail varies in width but is not less than 30 inches. Overgrown grasses narrow the trail in places.

Typical Grade: Level

Terrain: Moderately Firm


Situated at the north end of Shollenberger Park, Alman Marsh covers 80 acres of former pasture and marshland that was restored after the river levee was breached in the late 1980s. It is a biologically sensitive place, home to several threatened and endangered species. From Shollenberger, follow the loop trail counter-clockwise and in less than .25 miles you will cross the pedestrian bridge over Adobe Creek, then reach the entry to the mile-long Alman Marsh Trail on your left. This quiet path passes behind an office complex, crosses seasonal wetlands via several bridges, and eventually ends at a hotel parking lot.

Ellis Creek Water Recycling Facility Ponds (aka Ellis Creek)

Trailhead: Parking lot at the foot of Cypress Dr.

Length: 2-4 total miles

Typical Width: 4 ft. & above

Typical Grade: Level

There’s one gentle hill about .25 miles out.

Terrain: Moderately Firm

The dirt and gravel portions of the trail may be uncomfortable in a manual wheelchair.


The Ellis Creek water recycling facility is a great example of how a sewage processing and water purification plant can provide public and ecological benefits, from wildlife habitat restoration to recreational trails. Three miles of trails circle four elevated, bermed "polishing" wetlands, where heavy metals are removed in the final stage of water treatment. Tidal sloughs, a brackish marsh, mudflats, and riparian corridor occupy this expanse of open space; hills to the east and west provide the backdrop. Interpretive signs along the trails provide information about sewage treatment, wetlands, and the waterfowl and birds found here.

A few hundred feet from the trailhead, the trail splits. To the right, a .3-mile connector trail leads to Shollenberger Park; stay to the left to reach the ponds trails. At this junction, a lone stately oak beckoned for its picture to be taken. After a flat stretch you climb a gentle incline (the only one), and immediately after the trail changes from firm decomposed granite to dirt and gravel for the remainder of the way. Although bumpy, it was not problematic in a power wheelchair, but may be more challenging in a manual wheelchair. For the longest trip, circle each pond, or you can just make one big loop around their outer edges. Each pond seemed to offer a different experience. At the first two, swans cruised around the water while a great blue heron and a night heron stood onshore. At another, mallards cruised in and out of the water. The last is called Butterfly Pond and has an irregular shoreline to provide a beach and roosting areas for birds and waterfowl.

When you're done with your hike, be sure to check out the water conservation garden at the water recycling facility’s administration building, east from where you parked. The native plantings were colorful and attract butterflies, birds, and bees.

Accessibility Details

The facilities listed below meet all of our access criteria unless otherwise noted.

Accessible Parking: Yes

Shollenberger: Foot of Cader Ln. Ellis Marsh: End of Cypress Dr. Alman Marsh: An accessible space is at the trailhead in the public parking area within the Sheraton Hotel lot at the foot of Marina Ave.

Accessible Restroom: Yes

At the parking lots for Shollenberger and Ellis Creek

Accessible Picnic Tables: Yes

At Shollenberger, a few picnic tables are at the start of the trail and one is near the river, but all are dilapidated and uninviting.

Other Things of Interest

Petaluma Wetlands Alliance offers docent-led tours at Shollenberger and the Ellis Creek ponds on various Saturdays each month. Check the calendar for dates and times.
Polishing wetlands
Polishing wetlands (Bonnie Lewkowicz)

Features icon key

  • bicycling
  • hiking
  • picnic
  • wildlife viewing

Additional Information

View Map  
Managing Agency: City of Petaluma
Address: Cader Lane at S. McDowell Blvd.
Phone: (707) 778-4321
Hours: Dawn to dusk
Fees: None
Dogs: On leash
Public Transportation: Petaluma Transit
Useful Links: Petaluma Wetlands Alliance
Reviewed by Bonnie Lewkowicz, June 13, 2014
Access Norhtern California This web guide is a project of Access Northern California.  
California Coastal Conservancy Thanks to our partner the California Coastal Conservancy

DISCLAIMER: Although the information contained in this web-guide was believed to be correct at the time of publication, neither Access Northern California nor California Coastal Conservancy shall be held responsible or liable for any inaccuracies, errors, or omissions, nor for information that changes or becomes outdated. Neither Access Northern California nor California Coastal Conservancy assume any liability for any injury or damage arising out of, or in connection with, any use of this guide or the sites described in it.

Accessible Restrooms Icon looks like a women and men restroom signBeach Accessible
Wheelchairs Available
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