Geology and Geomorphology
Malheur National Wildlife Refuge is an oasis in the high desert of southeastern Oregon for the multitude of birds and other wildlife who make it their home. Situated in the wide open spaces of the Harney Basin on the northern edge of the Great Basin, the refuge encompasses a mere 292 square miles of the 5,300 square miles covered by the basin. The refuge includes vast cattail and tule wetlands, lakes, dry alkali playas, ponds, greasewood covered flats, lush native grass meadows, long corridors of riparian vegetation, and sagebrush covered hills bordered by impressive basalt rims. This great variety of wildlife habitats encompassed by the refuge begins in the lowest elevations of the basin and expands southward along the Donner und Blitzen River to the base of Steens Mountain and northwest into the lower reaches of the Silver Creek drainage.