The refuge contains over 5,600 acres (23 km2) of pastures, forested tidal swamps, brushy woodlots, marshes, and sloughs along the Columbia River in both Washington and Oregon.

By 2015, the deer population in the Lower Columbia River region, which includes Julia Butler Hansen and the Ridgefield National Wildlife Refuge, had doubled to 900, allowing the species to receive a recommendation to be reclassified as threatened.

[2] The valuable habitat the refuge preserves for the deer also benefits a large variety of wintering birds, a small herd of Roosevelt elk, river otter, various reptiles and amphibians including painted turtles and red-legged frogs, and several pairs of nesting bald eagles and osprey.

The areas upstream from the refuge on Puget Island and on the Oregon side of the river are vital to reestablishing and maintaining viable populations of the species.

This article incorporates public domain material from websites or documents of the United States Fish and Wildlife Service.