Morton Slough includes an important landscape feature along the Pend Oreille River. The Slough forms a large, shallow lake before it flows into a large, shallow bay on the Pend Oreille River. Historically, it supported exceptional wetland habitat before Albeni Falls Dam inundated all wetlands associated with the Pend Oreille River and Pend Oreille Lake. Now, the area is a shallow bay and shallow lake that supports shoreline wetlands, and aquatic plant beds. The shallow lake is held artificially higher than the River through a perched culvert in the road. The result is a relatively more biological productive condition in the lake.

Ornithological Summary

This site is still important to breeding and brood-rearing waterfowl, but is particularly important to migrating diving ducks (the Slough will become ice-covered in mid-winter during most years). Diving ducks (i.e., Redheads, Lesser Scaup, Common Goldeneye, Ring-necked Ducks, Buffleheads, Common Mergansers) are the most prevalent waterfowl, followed by American Wigeon, Mallards, and lesser numbers of Hooded Mergansers, Tundra Swans, Canada Geese, Canvasback, Gadwall, and Great Blue Herons. Total waterfowl numbers can exceed 2,000 individuals, although numbers will fluctuate throughout the migratory period. Morton Slough supports large numbers of waterfowl during late fall and early spring (up to mid-April). Shorebirds can be found here, as well as nesting Bald Eagles. Up to 25 Double-crested Cormorants, which are rare in the county, show up here in late fall.

Conservation Issues

Subdivisions and other residential development is occurring adjacent to the slough. No known conservation actions have been planned or implemented as of yet.


Shallow bay and slough adjacent to Pend Oreille River.

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