Floodplain data from the Hoh, Elwha, Queets, and Quinault Rivers in Olympic National Park, 1939-2013

Floodplain margins, defined as the unvegetated portion of the active flow zone, were determined for four rivers in Olympic National Park, Washington, USA, from the 2013 National Agriculture Imagery Program (NAIP) orthophotomosaic. Transects were established orthogonal to the active river corridor (braids) across the width of the floodplain from point locations placed at 250 m intervals along the main channel.