I have navionics and lake master and for south Dakota navionics just plain sucks. Get a lake master chip it’s awesome for the area. I believe the one I have has north and south Dakota and Nebraska. Lakemaster also has paper maps that are very detailed. Sportsmans cove in webser usually has a good supply of them. I like to look at the paper in the cabin to get ideas of where to fish the next day then use the Hbird with the lake master chip when on the water.