Extending along the east bank of the Columbia River from the confluence of the Snake River to the mouth of the Walla Walla River and downstream into Oregon, the McNary National Wildlife Refuge preserves a priceless diversity of fish, wildlife, and plants. McNary Refuge serves as an anchor for biodiversity and ecosystem-level conservation. Refuge bays and shorelines are critical nurseries for developing fall Chinook salmon; and passageways for endangered steelhead, sockeye, and Chinook salmon stocks. Up to half of Pacific Flyway mallards winter in this portion of the Columbia Basin. The Wallula Delta is the premiere habitat in the region for thousands of migrating shorebirds and wading birds. Rare and endangered birds, including bald eagles and peregrine falcons, are found here, as are thousands of colonial nesting water birds using river islands for safe nesting. Encompassing more than 15,000 acres of Columbia Basin desert and river environment in eastern Washington, refuge habitats include rivers, backwater sloughs, shrub-steppe uplands, irrigated farmlands, river islands, and delta mud flats.