This wildlife refuge consists of two units. The largest is Topock Gorge, south of the junction of Interstate 40 and the Colorado River; it is accessible only by boat or on foot. The second unit, Topock Marsh, begins north of Interstate 40 on the Arizona side of the Colorado River and continues for 11 miles. Also included is the 18,000 acre Havasu Wilderness Area.
The 37,515-acre refuge is the home of some of America's rarest birds, the Southwestern Willow Flycatcher and the Yuma clapper rail. Other species sheltered at the refuge include migratory birds, beavers and bighorn sheep. Humting and fishing (in season) are permitted, as are boating and camping in designated areas.
