[4] The elongated park includes a shallow seasonal lake and wetland, open grassy areas, and mixed maple and oak woodlands, among other habitats.

[3] The plan in the early 1970s was to fill the rest of the wetlands and to use the space for museums, perhaps a motocross course, and a gondola lift to transport visitors from the top of the bluff to the park.

[3] Public pressure from the Audubon Society of Portland, the Sellwood-Moreland Improvement League, and The Nature Conservancy helped persuade the city to stop filling the wetlands.

[3] Since then, Friends of Oaks Bottom, a volunteer group, has helped the city's parks department with trail maintenance, habitat restoration, and information services.

[4] As of 2010, more than 185 bird species have been recorded in the refuge including herons, egrets, hawks, osprey, shorebirds, gulls, terns, hummingbirds, woodpeckers, grebes, falcons, vultures, waterfowl, and many others.

[3] Invasive species, gradually being replaced by physical removal and burning, include reed canary grass, purple loosestrife, Himalayan blackberry, and others.