A wildlife management area owned by the BLM and Bureau of Reclamation, and is jointly managed by these two agencies, and the Arizona Game and Fish Department (AZGFD). It consists of about 1100 acres of marsh and open water formed from Colorado River backwaters, old channels, and some dredging. The Wildlife Area includes Clapper Rail and Black Rail marsh habitat named Teal Alley, YPG Slough, and YPG West. Mittry Lake is downstream of Imperial Dam and is within the highest densities of California Black Rail populations on the lower Colorado River.

Ornithological Summary

This area contains some of the largest populations of Yuma Clapper Rails and California Black Rails in the southwest. Good marsh habitat for other birds such as Virginia Rail, Sora, Least Bittern, and American Bittern. A large wintering population of American Coots (>5000 individuals) uses the area. Provides habitat for migrating Southwestern Willow Flycatchers and other neotropical birds. The area provides foraging and nesting habitat for herons and egrets, and supports a population of Burrowing Owls.

Conservation Issues

Tamarisk invasion is a major issue regarding the degradation of the riparian habitat. Increasing selenium levels also pose a significant threat to local bird populations. Leakage from the Gila Gravity Main Canal has created marsh habitat, that would be lost if this canal were lined. Fire burning widely in non-native vegetation is a threat.


A state of Arizona wildlife area managed by the Arizona Game and Fish Department and jointly owned by the U.S. Bureau of Land Management and Bureau of Reclamation.


Marsh and open water. Most riparian habitats have been overgrown by tamarisk. Some areas overgrown by phragmites. Some projects are planned to clear this vegetation and establish cottonwoods and willows.

Land Use

Fishing is the primary recreational use, followed by hunting, and wildlife conservation.

Protected Areas:
None. Open to hunting.

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