Of 99 counties in the state, Obrien County ranks 46th by size (573 square miles). Obrien County is in Western Iowa. Recent Land Network data includes around 1,000 acres of lakefront land and property for sale in Iowa's Obrien County, which is valued at a combined $1 million. Browse all waterfront property for sale in Obrien 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 Obrien County is house.