Floods of June 24-25, 1966 in southwest-central North Dakota

A severe thunderstorm accompanied by much hail swept through southwest-central North Dakota on the afternoon of June 24.  Rainfall of up to 13 inches caused floods higher than any previously known in the area.  The isohyetal map (fig. 1) indicates the extent and magnitude of the storm. This map was derived from rainfall data at 20 U.S. Weather Bureau gages (4 recording), 26 Geological Survey gages (5 recording) and 124 sites located in a bucket survey made by the Geological Survey (table 1).