Marysville, the county seat of Marshall County, is a beautiful and prosperous town located near the Big Blue River in northern Kansas. Established in 1854, Marysville is the oldest civilian post office in continual operation in Kansas. Along with several history museums and attractions, you’ll find multiple parks, a themed playground, a zero entry swimming pool, a hiking/running/biking trail that connects to a trail system in Nebraska, 18 dining options and 150 motel rooms. While history is a valued asset, we pride ourselves on the people and progress of Marysville. With a population of 3,280, Marysville is located at the junction of US Highways 36 & 77 in northern Kansas.