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Oso Flaco Lake and the Guadalupe-Nipomo Dunes

Oso Flaco Lake lies within the Guadalupe-Nipomo Dunes National Wildlife Refuge, the largest remaining coastal dune system in California and an important breeding area for several imperiled species, including the western snowy plover, California least tern, and California red-legged frog. The lake is within the Oceano Dunes State Vehicular Recreation Area, but is off-limits to the noisy off-road vehicles that frequently swarm nearby. Enjoy the natural quiet at the lake.

In 1923, Cecil B. DeMille’s The Ten Commandments was filmed in the Nipomo Dunes and the sets were later buried beneath the sand; more recently, Pirates of the Caribbean: At World’s End was shot in the dunes. Picnic tables and benches alongside an accessible trail offer plenty of opportunities to enjoy the rare coastal lake as well as abundant birds and wildlife. A boardwalk crosses the lake, then travels through dunes, which support more than 1,000 species of plants and animals.

Visitor center: Located in a restored 1910 Craftsman-style bungalow, three miles south of Oso Flaco Lake in the town of Guadalupe. On the wheelchair-accessible first floor you can see a treasure of period furnishings and accurately restored elements of the Craftsman style. The second floor is not accessible, but the videos that are shown upstairs can be shown downstairs upon request. Among these videos is a fascinating story about the Dunites, a community of artists and free spirits who lived in the dunes during the Depression; another details the making of The Ten Commandments.

Trail/Pathway Details

Dune Trail

Trailhead: Lot at foot of Oso Flaco Lake Road

Length: 1-2 total miles

Typical Width: 4 ft. & above

Overgrown plants narrow the path in some sections, possibly preventing access for some manual wheelchair riders.

Typical Grade: Mostly level or gentle

Some sections of boardwalk through the dunes has a significant cross slope and undulates quite a lot becaiiuse of the shifting sand.

Terrain: Hard

The first section of trail is hard-packed dirt and can be muddy during the rainy months. Sand blown across the boardwalk in some places may prevent passage.


The one-mile Dune Trail travels through three very different environments—woodlands, wetlands, and dunes—and is excellent for spotting birds. You travel the first few hundred yards on firm dirt through streamside woodland, with arroyo willows, wax myrtles, and other trees providing a canopy of shade—something you won't find elsewhere on the trail. You can hear the burbling creek, the music of birdsong, rustling trees, and waves crashing in the distance. Shortly after you begin to see tule and other water plants, turn left onto the boardwalk. (The dirt trail continues uphill a short distance, then ends in sand.)

The boardwalk travels slightly uphill, then levels out. As you cross Oso Flaco Lake on a footbridge, stop at one of the viewing areas for a closer look. You may see ruddy ducks, least terns, gadwalls, swallows, and other birds, though a 36-inch railing running the length of the boardwalk may block the view for some wheelchair riders.

After crossing the lake, the route climbs a moderate slope onto the dunes, where stretches of undulating boardwalk have a cross-slope that may pose challenges for those using manual wheelchairs. The landscape here changes to coastal scrub, which during my visit in late October was blooming with Hooker's evening primrose and silver bush lupine. In several places the lupine had overgrown the boardwalk, narrowing the path to less than 30 inches, but it was easy to push the plant aside with my hands and get past it in my motorized wheelchair. Soon you come to a trail junction by a picnic area and information board. Conitinue forward another 100-feet to an elevated platform overlooking the dunes. If you instead take the short spur trail it ends at a fence in .2 miles. 

Accessibility Details

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

Beach Wheelchair: Yes

Available seven days a week, 10 am-4 pm. Best to call several days in advance to reserve: Dunes Center: (805) 343-2455; Oceano Dunes Ranger Station: (805) 473-7220; or ask entrance station attendant at Oso Flaco.

Accessible Parking: Yes

Multiple accessible spaces at trailhead

Accessible Restroom: Yes

Vault units at trailhead and at the spur trail at .75 miles that leaves from the large deck with picnic tables.

Accessible Picnic Tables: Yes

On boardwalk over lake and at a large deck close to the end of the trail.

Other Things of Interest

Some 12 miles south of Oso Flaco is Rancho Guadalupe Dunes Preserve, where you can see great expanses of the dunes from your car and there is level access onto the dunes. 
New overlook where trail ends
New overlook where trail ends (Dan McElhinney, Guadalupe-Nipomo Dunes Center)

Features icon key

  • Beach Wheelchairs Available
  • hiking
  • picnic
  • wildlife viewing

Additional Information

View Map  
Managing Agency: California State Parks
Address: 3098 Oso Flaco Lake Rd.
Phone: (805) 473-7223
Hours: Daily, sunrise to sunset
Dogs: Not allowed

Did You Know?

Sedges have edges, and rushes are round, and reeds are hollow right down to the ground. 

Reviewed by Bonnie Lewkowicz, June 29, 2007
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
  Hiking icon is silhouette of a hikerHiking & Trails
Biking icon looks like person riding a bikeBicycling   Good for Familis icon is a child on a swing'Particularly Good for Families
Boating Icon is a boatBoating   Picnic Area Icon is a picnic tablePicnic
Camping icon is a tentCamping   Swimming Icon is a person swimmingSwimming
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