[citation needed] Geographically, the area is part of the Columbia River Plateau, formed by basalt lava flows and water erosion.

The sagebrush-bitterbrush-bunchgrass lands are home to a wide variety of plants and animals, and the Hanford Reach provides one of the northwest's best salmon spawning grounds.

Islands, riffles, gravel bars, oxbow ponds and backwater sloughs provide support to forty-three species of fish.

Mammals that inhabit this refuge include coyotes, skunks, beavers, mule deer, bobcats, river otters, minks, cougars and badgers.

The monument is open from two hours before sunrise to two hours after sunset; some areas are open to the public and others are not: Several sites in the adjacent Hanford Site including the B Reactor are part of the Manhattan Project National Historical Park and are accessible on public tours.