For the more information about the air resources of the National Park Service, please visit http://www.nature.nps.gov/air/.
Grand Coulee is an illustration of a series of geological events including outpourings of lava, advance and recession of glacial ice, retreat of waterfalls, and the cutting of the Columbia River channel.
Location: Grant County, WA
Year designated: 1965
Ownership: Federal, State, Private
Please remember, National Natural Landmarks (NNLs) are not national parks. NNL status does not indicate public ownership, and many sites are not open for visitation.
Last Updated: June 28, 2012