[1] The lake bed soils contain a layer of organic peat that once supported a wetland community dominated by the wapato plant, Sagittaria latifolia, particularly in the upper marsh areas.

[3] The lake area was 800 to 1,500 acres (320 to 610 ha) before it was drained in the mid-1930s by the Wapato Improvement District—created by local landowners—which installed ditches, dikes, and drainage tiles to increase available farmland,[2] primarily for cultivation of onions.

[8] Wapato Lake Unit is located about 15 miles (24 km) to the west of the main refuge, near the city of Gaston along Oregon Route 47 in Washington and Yamhill counties.

[13] Valley forests, prairies, and wetlands encompass the region today,[10] including two small streams, Ayers and Wapato creeks.

[10] Totaling 180 acres (73 ha) from three properties, the Fish and Wildlife Service paid $631,000 for the land using a grant from the Migratory Bird Conservation Commission.

[10] On March 18, 2023 the Wapato Lake National Wildlife Refuge was officially opened to the public in a ceremony at Gaston High School.