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Mother Lode Field Office

Cosumnes River Preserve

 NOTICE:  The Cosumnes River Preserve Visitor Center will be CLOSED from
 June 20th until approximately October 25th for enhancements and repairs.

Parking lots, vault toilets, trails, and access to the river via the boat launch
will remain OPEN for the duration of the renovation.
Preserve staff will be working from an alternate location
 but normal presence and services will continue during this period.

  For any questions, please contact the general information line at 916-684-2816
 or via email at
Please also visit Cosumnes River Preserve News

Wetland habitat at the Cosumnes River Preserve, Photo by BLM

The Cosumnes River Preserve is home to California's largest remaining valley oak riparian forest, and is one of the few protected wetland habitat areas in the state.

This habitat has been reduced by more than 90% of its historical occurrence in California.

The Preserve includes 46,000 acres of central valley grasslands, vernal pools, wetlands and valley oak forests.

The Cosumnes River is the only remaining unregulated (undammed) river on the western slope of the Sierra Nevada Mountains. In its lower reaches, it flows through one of the most biologically rich regions in California's Central Valley, before merging with the Mokelumne River to flow into the Sacramento-San Joaquin Delta and eventually the Pacific Ocean. The Cosumnes River Preserve was created to safeguard much of this unique landscape.

Sandhill Cranes at Cosumnes River Preserve, Photo by Bob Wick, BLM


Nestled in the heart of California's Central Valley, The Preserve is a critical stop on the Pacific Flyway for migrating and wintering waterfowl.

Over 250 species of birds have been sighted on or near the Preserve, including the State-listed threatened Swainson hawk, greater and lesser sandhill cranes, Canada geese and numerous ducks.  

Visit Cosumnes River Preserve Homepage 
You will find educational, recreation and volunteer opportunities

Cosumnes River Preserve’s Vision Statement:

“The Cosumnes River Preserve Partners envision the permanent protection of a continuous riparian corridor extending from the Cosumnes headwaters to the Delta, including adjacent floodplain and wetland habitats, and a vast vernal pool grassland complex supporting endangered species.

The Partners will utilize stewardship and compatible ranching and farming activities as methods to sustain native plant and wildlife communities and the processes that perpetuate a dynamic mosaic of habitats.

We will provide opportunities for people of all ages to appreciate the flora and fauna of the Cosumnes River Preserve and to experience being part of a natural landscape.” 

Cosumnes River Preserve’s Final Management Plan

 Riparian habitat at Cosumnes River Preserve, Photo by BLM

Mission of the Cosumnes River Preserve:

  • Safeguarding and restoring the finest remaining example of California Valley oak riparian (stream side) ecosystem and its surrounding habitats.
  • Restoring and creating freshwater wetlands to increase the Pacific Flyway´s populations of migratory waterfowl.
    Demonstrating the compatibility of human uses-- particularly agriculture, recreation, and education-- with the natural environment.


The Cosumnes River Preserve Partnership:

The Cosumnes River Project began with an 85 acre plot purchased by The Nature Conservancy in 1984. As partnering agencies joined the project, they formed the Cosumnes River Preserve in 1987. Today it is larger than 46,000 acres, or approximately 72 square miles – an area that is greater than the City of San Francisco. The bulk of the property stretches east to west along the Cosumnes River corridor, between Interstate 5 and Highway 99.

Seven of the nine partners own land in fee title at the Cosumnes River Preserve. Through the use of conservation easements, private land owners also contribute to the total area which is now permanently protected by the Preserve. The seven land-owning partners are:

Bureau of Land Management - Mother Lode Field Office
California Department of Fish and Game
Ducks Unlimited, Inc.
California Department of Water Resources
Sacramento Co. Dept. of Regional Parks
The Nature Conservancy
Wildlife Conservation Board
California State Lands Commission

Visit our "partners" homepage Cosumnes River Preserve 

A significant portion of Preserve lands, including most of the conservation easements, are utilized for agriculture and grazing. Responsible farming practices can benefit resident and migratory wildlife by providing both food and habitat. Remnants of grain harvests spread seeds for critters to collect, flooded rice fields provide ponds for waterfowl and cattle grazing promotes the growth of wildflowers in vernal pools by controlling grasses.

All of the Preserve lands are permanently protected from urban and commercial development either through fee title ownership by a Preserve partner or by protection in perpetuity by a conservation easement. Conservation easements are purchased from willing sellers. When the preserve purchases a conservation easement from a willing seller, all of the landowner’s rights are reserved to the landowner with the exception of the right to develop the property for urban or commercial uses.

The Cosumnes River Preserve is approximately 20 miles south of Sacramento, the state capital of California. This region has experienced rapid growth and urban sprawl, which has converted agricultural fields and open space into strip malls and suburban neighborhoods. This expansion has significantly reduced the amount of prime habitat available to both resident and migratory wildlife.

Mailing Address:
Cosumnes River Preserve
13501 Franklin Boulevard
Galt, California 95632

Phone Number: (916) 684-2816 
Fax Number:(916)683-1702

From Sacramento, take Interstate 5 south, and exit at Twin Cities Road. Head east on Twin Cities Road to Franklin Boulevard, and then turn south. Continue on Franklin Blvd. and go past Desmond Road, then proceed two-tenths of a mile to the Willow Slough Nature Trail on the left. The Willow Slough Trail, a three mile loop, is open during daylight hours with parking on the west side of Franklin Blvd. at Lost Slough Boardwalk.

From the Willow Slough Trailhead, you can continue south on the new trail for 0.2 miles to the Lost Slough Wetlands Boardwalk. The Boardwalk is on the right (west) side and continues south to the Visitor Center.  The trail is one mile and is wheelchair accessible. The Lost Slough Wetlands Boardwalk is open daily from 9:00 am to 4:00 pm.

The Cosumnes River Preserve Visitor Center is another four-tenths of a mile south along Franklin Blvd on the left (east) side.

The Visitor Center is open and staffed by volunteers on Saturday and Sunday from 9:00 am to 5:00 pm,  including holidays.  Open on weekdays, but hours vary.  The Visitor Center deck and outdoor exhibits are open to the public even when the indoor exhibit room is closed.

Cosumnes River Preserve Visitor Center, Photo by BLMThe Nature Conservancy acquired the first property along the Cosumnes River in 1984. Ten years later a visitor center was constructed but an arson fire in 1995 damaged the structure beyond repair. The remains were torn down and the current facility was completed in 1997.

This building houses an exhibition room with interpretive displays and operates as an office for staff of the various partners, including the Bureau of Land Management, The Nature Conservancy, Sacramento Co. Dept. of Regional Parks and California Department of Fish and Game.


Visitor Activities:
The trails, boardwalks and waterways are the only parts of the Preserve that are open to the general public. These areas are open from sunrise to sunset. The Visitor Center is staffed by volunteers on the weekends and Preserve staff tries to keep it open during the weekdays. The Preserve promotes low impact recreation and offers naturalist-lead activities that include: hikes, bird monitoring, paddles, photography walks and more. 

The Preserve’s Wood Duck Program is associated with a statewide effort that has been supported and coordinated by the California Waterfowl Association since 1991, when the California Wood Duck Program first began. An organized group of volunteers monitors, maintains, builds and replaces the 160 Wood Duck boxes located on the Preserve.

Volunteers also take an active role in managing and monitoring bird nest boxes for western blue birds and tree swallows. Nest box monitoring began in 2003 and its 67 boxes are part of a greater project studying tree swallows and their tropical nearest relatives from Alaska to Argentina.

NO dogs are allowed: 
The mere presence of dogs, and other domestic pets, can create momentary and prolonged disturbances to local wildlife. Dogs are perceived by many animals to be predators. This will cause creatures to alter their behavior and may discourage them from foraging or breeding.

This rule is also in place for the safety of you and your pet. There are some animals that are potentially harmful to your dog, like mountain lions and venomous snakes. Pets also attract parasites, like ticks and mosquitoes, and increase the risk of exposure to poison oak.

The Visitor Center and the Lost Slough Wetlands Boardwalk are wheelchair accessible.

Camping and Lodging facilities:
Camping is NOT allowed on the Cosumnes River Preserve. Commercial facilities offer lodging in Sacramento, Galt, and Lodi.

Food and Supplies:
Food and supplies are not available on-site. The nearest sources are in Sacramento, Galt, and Lodi.

First Aid:
No first aid is available on-site. The nearest hospital is located in Sacramento.

Additional Information:
The best time to observe waterfowl is during the winter months. Many species of waterfowl spend their winters in the warmer climates that are south of the arctic freeze. Remains of the fall harvest and winter flooding provide ideal habitat for a variety of species that journey along the Pacific Flyway. Waterfowl, cranes, wading birds, and shore birds are seen from October to March; birds of prey from November to April. Songbirds are common in the fall and spring. Small boat access to Lost Slough from Delta Meadows Park.

What to bring:
When visiting the Cosumnes River Preserve, binoculars or cameras are nice things to bring. Also, sun protection, water, a light jacket, snacks and a trash bag.

Insect repellent is highly recommended, especially in spring and summer when ticks and mosquitoes are most active. There are no tick-related lyme disease cases in Sacramento County, but there is still the potential for these parasites to carry harmful diseases.

Bureau of Land Management
Mother Lode Field Office
5152 Hillsdale Circle
El Dorado Hills, CA 95762
Phone: (916) 941-3101
Fax: (916) 941-3199
Office Hours:
 8:30 a.m. - 4:30 p.m., M-F
Contact us by Email