The Ottawa River, also known as Ottawa Creek, is a short river, approximately 20 miles long, in northwest Ohio and southeast Michigan in the United States. It drains an area on the Ohio-Michigan border along the eastern and northern fringes of the city of Toledo, goes through Ottawa Hills, and empties directly into Lake Erie. It is one of two rivers in nort…The Ottawa River, also known as Ottawa Creek, is a short river, approximately 20 miles long, in northwest Ohio and southeast Michigan in the United States. It drains an area on the Ohio-Michigan border along the eastern and northern fringes of the city of Toledo, goes through Ottawa Hills, and empties directly into Lake Erie. It is one of two rivers in northwestern Ohio that share the same name, along with the Ottawa River that is a tributary of the Auglaize River. The upper 4 miles of the river in Michigan north of Sylvania, Ohio is called North Tenmile Creek on federal maps, while another branch rising in Fulton County, Ohio, is called Tenmile Creek.