California Department of Fish and Wildlife

Grizzly Island Wildlife Area's Self-Guided Tour

The California Department of Fish and Wildlife's Grizzly Island Wildlife Area consists of 8,600 acres located in the heart of the 84,000-acre Suisun Marsh. The Suisun Marsh is the largest contiguous estuarine marsh in the United States. Grizzly Island provides habitat for more than 200 species of birds and is home to a variety of threatened or endangered wildlife and plants. Enjoy your visit!

Grizzly Island may be closed to public access at certain times; please refer to the public use schedule below.

The Self-Guided Tour begins at the Area Headquarters and continues for about 7 ½ miles along Grizzly Island Road, which is unpaved and runs through the middle of the Wildlife Area. Some things you may need for an outing at Grizzly Island: binoculars, field guide, drinking water, sun block, insect repellent, jacket, and appropriate footwear. Please abide by all signs and area regulations. Some points of interest are listed below by parking lot locations. Grizzly Island Wildlife Area's Headquarters Office is open Monday-Friday, 8am - 4:30pm. The headquarters office has free literature and a collection of mounted birds. If you visit while the office is closed, please view our outdoor kiosks for interesting information about Grizzly Island.

Parking Lot 1 - Approaching parking lot 1 you will pass large grassy fields to your left. During the spring, these upland fields have some of the highest nesting densities of waterfowl found anywhere in California. They are also nesting areas for northern harriers and short-eared owls. From the parking lot, walk toward the check station to scan the fields for tule elk, birds of prey or grazing waterfowl. Look at the outflow of the nearby pump where turbulent water sometimes attracts river otters. The large pond adjacent to lot 1 is managed to encourage pickleweed, which is the preferred habitat of the endangered salt marsh harvest mouse.

* Parking Lot 1A - A viewing platform has been built on a levee at this site for the public's nature viewing enjoyment.

Parking Lot 2 - Walking down the levee road southwest from lot 2 (past the yellow gate) is a good place to see warblers, goldfinch, and sparrows in the brush, especially during spring migration. These fields also are used as a spring grazing area for some of the resident tule elk. Roaring River Slough at the end of the levee road provides some excellent striped bass fishing. As you continue driving down Grizzly Island Road, you will be following Grizzly Ditch, which is a good place to look for otters. About 1 mile from parking lot 2 you can turn left onto Red House Road and often see raptors such as rough-legged hawks, northern harriers, or red tailed hawks. Tule elk may also be seen in this area. Turn around at the yellow gate and go back to Grizzly Island Road, turn left to continue the tour.

Parking Lot 3 - From lot 3 it's a nice hike over the footbridge (look both ways for vehicles and otters) and follow levees back to Howard Slough. Waterfowl concentrations in this area can be phenomenal during early fall and late winter, and tule elk may be seen in the distance. Striped bass fishing is available in Howard Slough. Beware of steep banks.

Parking Lot 4 - The area around parking lot 4 is a popular fishing site. During wet years, water is fresher and catfish, crappie, largemouth bass and stripers may be caught. A walk south down the road through the yellow gate is the quickest route to Howard Slough where you may see diving ducks. North of lot 4 is Pond 11, a good place to look for American Bitterns and waterfowl.

Parking Lot 4A - This small parking lot gives access to a deep-water pond to the north. It's a nice walk around this pond; you may see diving ducks and the levee provides some elevation to scan the horizon for raptors and tule elk.

Parking Lot 5 - North of lot 5 is upland habitat where tule elk can sometimes be found. To the south is a footbridge, which allows access to ponds along Steve's Ditch. Bushy sides of levees in this area are at times inhabited with migratory warblers. White-tailed kites are often seen perching on the coyote bushes in this area.

Parking Lot 6 - From lot 6 the pond to the north is one of the better areas to look for diving ducks and the surrounding vegetation is teeming with bittern, moorhen, Virginia, and sora rail. The listed black rail has been heard in these tules late at night in the spring. Directly past lot 6 is Montezuma Slough, which meanders around the eastern, northern and western edges of Grizzly Island and is the water supply for most of the ponds. If you turn right along Montezuma Slough you will see the Dept. of Water Resources' salinity control gates for improving water quality in the marsh. Three disabled accessible piers extending over the slough provide excellent fishing access.

Parking Lot 7 - Turning left at Montezuma Slough takes you past the outlet to Grizzly Ditch and Dutton's Pond. This pond should be checked for river otters and diving ducks. From lot 7 you can either walk along Montezuma Slough or to the west along Poleline Road.

This concludes the Self-Guided Tour. Please return your Use Permit to the green post at the Area's Headquarters as you leave.

* Complete Area Regulations for hunting, fishing, and other uses can be found at