Ice is probably just coming off. Never been there. Usually crappies move shallow once the ice comes off and have decent luck if the weather stays nice.
Yeah I fish the Mississippi from Muscatine up to Lansin Iowa, some places are not accessible by a regular boat (mud flats). I'm looking for different places to crappie fish I remember going to rathbun when I was a kid and the fishing was really good but it's a little bit to far away for a day trip.