Cosumnes River Ecological Reserve


river flowing between trees
Photo courtesy of the California Wildlife Conservation Board

The Cosumnes River is the only unregulated river on the western slopes of the Sierra Nevada. Because it remains undammed, it experiences the seasonal overbank flooding that was once a common feature of rivers in California's central valley. This flooding supports the natural growth of riparian and floodplain vegetation, which in turn serves as home to an astounding array of wildlife. More than 250 bird species, over 40 fish species, and approximately 230 plant species have been identified on the approximately 4,700 acre reserve. These include various species of egrets and herons, sandhill cranes, stilts and avocets, phoebes and flycatchers, and yellow and Wilson’s warblers. The property was designated as an ecological reserve by the Fish and Game Commission in 2003, and includes the Dillard, Arno, and McFarland Units.

For more information, visit the Cosumnes River Preserve website(opens in new tab) or call the North Central Region Rancho Cordova office at (916) 358-2900.

Recreational Opportunities

fishing  Hiking Trails Restrooms

Activities: Fishing, hiking, and hunting. There are designated launching sites for launching lightweight, hand-carried, non-gasoline powered floating devices.

Deer hunting opportunities have been expanded in 2023 and now include early season archery-only hunts within the A Zone at the Cosumnes River Ecological Reserve in addition to the general season hunts. See the news release for details. Access the deer hunt applications at the following links:

Facilities: Restrooms available at the Visitor's Center

NOTE: Visitors are responsible for knowing and complying with all regulations pertaining to the use of Department lands.

Refer to the Public Uses on State and Federal Lands section of the Waterfowl, Upland Game, and Public Use Regulations (PDF) booklet for both statewide and property-specific regulations.

no drones icon
You may not operate a drone on CDFW Lands without a Special Use Permit.

Related Documents

Map of Cosumnes River ER - click to enlarge in new window
Click to enlarge


North Central Region (Region 2)

Sacramento County

off Interstate 5 between Sacramento and Stockton


From I-5 North: Take Interstate 5 to the Twin Cities Road exit (marked with a binoculars sign for wildlife viewing) about midway between Stockton and Sacramento. Take Twin Cities Road exit and go East for exactly one mile, to the first stop sign. Turn right at the first stop sign, onto Franklin Boulevard, for 1.7 miles. The Visitor Center is located on the left side of Franklin Boulevard. Continue down Franklin Boulevard and park in the parking lot just past the Visitor Center.

From I-5 South: Take Interstate 5 to the Thornton-Walnut Grove Road exit. Go east towards the Chevron gas station and turn left immediately after the Chevron station onto Thornton Rd. Follow Thornton Road north for about 2 miles and it will turn into Franklin Boulevard, continue north on Franklin crossing over the Thornton-Franklin bridge. The Visitor Center and parking are on your right, just after the bridge.

From Highway 99: Take Highway 99 to the Twin Cities Road exit about midway between Stockton and Sacramento. Take Twin Cities Road west for about 6 miles and turn left onto Bruceville Road. Continue south on Bruceville Road and at the end turn right onto Desmond Road. Follow Desmond Road for about a mile over the Railroad tracks and turn left onto Franklin Boulevard. Continue down Franklin Boulevard and park in the parking lot just past the Visitor Center.

CDFW Lands Viewer