Johnson County, NE lies in southwestern Nebraska with an estimated population of about 2,800 people living across 641 square miles of land. The county seat is Tecumseh while its largest city is Tecumseh. Johnson County offers visitors a variety of attractions ranging from historical sites such as Fort Robinson State Park to unique modern spots like Johnson Reservoir Ranches ideal for bird watching, kayaking or camping along the banks of the Platte River and Niobrara River.