SIOUX FALLS, S.D. (KELO) -- Authorities in western South Dakota are assisting with traffic control on Interstate 90. Pennington County broke 2 open-meetings laws The Pennington County Sheriff's Office says there have been multiple "significant crashes" on I-90 east of Wall. The interstate is currently closed at Mile Marker 125. According to the SD 511 website, I-90 east of Wall to the Cactus Flax exit is closed.