Saginaw (săg´Ĭnô), city (1990 pop. 69,512), seat of Saginaw co., S Mich., on the Saginaw River, 15 mi (24 km) from its mouth on Saginaw Bay (an inlet of Lake Huron); settled 1816, inc. 1857. Situated in an extensive agricultural area, Saginaw is also a port of entry. Machinery, animal feeds, metal products, automobile parts, concrete, and electrical equipment are manufactured, and there is food processing. Nearby are salt, coal, and oil deposits. Native American trails once crossed the city's site, and local native villages were abundant. Lewis Cass negotiated a treaty there (1819) with the indigenous groups, who ceded much of Michigan to the United States. Fur trade was followed by a great pine-lumbering industry, which thrived until about 1890. Saginaw Valley State Univ. is there.

Saginaw, river, 22 mi (35 km) long, formed by the confluence of eight branches, SE Mich. The river drains a large area of lower Michigan and flows into Saginaw Bay (c.60 mi/100 km long and 15–25 mi/24–40 km wide), an arm of Lake Huron. Bay City, a port, is located at the bayhead near the river's mouth, and Saginaw is located upstream. Coal, pig iron, salt, and oil are transported on the river.