Big Sandy Lake is a lake in Aitkin County, Minnesota, approximately nine miles north of McGregor. The lake is considered fertile walleye ground with several habitat types, including the open main basin, the deep, cold eastern basin, and a shallow, more isolated south basin. Shallow bays containing dense beds of wild rice are found on south, west, and nort…Big Sandy Lake is a lake in Aitkin County, Minnesota, approximately nine miles north of McGregor. The lake is considered fertile walleye ground with several habitat types, including the open main basin, the deep, cold eastern basin, and a shallow, more isolated south basin. Shallow bays containing dense beds of wild rice are found on south, west, and northwest sides of the lake.