May 15, 2015
After a snow storm on May 9-10 left a liquid equivalent of one to three inches of precipitation over southwestern South Dakota and northwestern Nebraska, additional rain combined with the melting snow to cause flooding in the White River, Cheyenne River, and Bad River basins. Record flooding was recorded on the White River in Shannon County.
Source: NOAA National Weather Service Storm Events Database (event 576887). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Oglala Lakota County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.