Steuben County is a county in the U.S. state of Indiana. As of 2010, 34,185 people lived there. The county seat is Angola.Steuben County covers roughly 1397 square miles with a population of approximately 100,000 people living in rural agricultural areas, quaint small towns, and small city communities. Many of theirs streets, towns, rivers, and lakes in the area, like Keuka Lake, have names which reflect the influence of the Seneca Indians who lived here long before it became Steuben County.