The smallmouth bass (Micropterus olomieu) is a species of freshwater fish in the sunfish family (Centrarchidae) of order Perciformes. It is the type species of its genus. One of the black basses, it is a popular gamefish sought by anglers throughout the temperate zones of North America, and has been spread by stock to many cool-water rivers and lakes in the United States and Canada. The smallmouth bass is native to the upper and middle Mississippi River basin, the Saint Lawrence River–Great Lakes system, and up into the Hudson Bay basin. Its common names include Smallmouth, Bronzeback, Brown Bass, Brownie, Smallie, and Bronze Bass.