Grand River, MI

The Grand River is the longest river in the U.S. state of Michigan. It runs 252 miles (406 km) through the cities of Jackson, Eaton Rapids, Lansing, Grand Rapids, and Grand Haven.  The Grand river begins in Somerset Township in Hillsdale County, and in Liberty Township in Jackson County, and flows through Jackson, Ingham, Eaton, Clinton, Ionia, Kent, and Ottawa counties before emptying into Lake Michigan.

Its watershed drains an area of 5,572 square miles (14,430 km²), including 18 counties and 158 townships. The Grand River carries an average 3,800 ft³/s (108 m³/s). It has several dams along its length but is a trout and salmon stream for much of its length. Tributaries are the Flat River, Looking Glass River, Maple River, Red Cedar River, Rogue River, Coldbrook Creek, Plaster Creek, Crockery Creek, and the Thornapple River.

During the ice age era the lower Grand River was part of a glacial river that drained Saginaw Bay into Lake Michigan. The outflow then poured over the Chicago divide and flowed down the Illinois River and Mississippi River.

Grand Rapids was built on the site of a large rapids on the river, although these have disappeared after the installation of a low-head dam, and later a fish ladder.