The Amite River is a tributary of Lake Maurepas in Mississippi and Louisiana in the United States. It is about 117 miles long. It starts as two forks in southwestern Mississippi and flows south through Louisiana, passing Greater Baton Rouge, to Lake Maurepas. The lower 37 miles of the river is navigable. A portion of the river is diverted via the Petite A…The Amite River is a tributary of Lake Maurepas in Mississippi and Louisiana in the United States. It is about 117 miles long. It starts as two forks in southwestern Mississippi and flows south through Louisiana, passing Greater Baton Rouge, to Lake Maurepas. The lower 37 miles of the river is navigable. A portion of the river is diverted via the Petite Amite River and Amite Diversion Canal to the Blind River, which also flows to Lake Maurepas.