Of 66 counties in the Coyote State, Gregory County ranks 30th in terms of size (1,053 square miles). Gregory County is in Great Lakes South Dakota. Recent Land Network data totals around 1,000 acres of riverfront land for sale in South Dakota's Gregory County, which is valued at a combined $4 million. Browse all waterfront property for sale in Gregory County on the Land Network to find the marina, lakefront and other recreational property that meets your needs, from waterside land perfect as a retirement investment to existing residential waterfront land and property for hunting, fishing and other outdoor-recreation pursuits! The most common type of land for sale by combined acreage in Gregory County is recreational property.