Since 1870 several unsuccessful attempts have been made to establish Pacific salmon in the Great Lakes. In 1966 at this site the Department of Conservation released coho fingerlings, hatchery-reared from eggs given by the state of Oregon. They migrated to Lake Michigan and fed on its enormous alewife population. Augmented by subsequent annual plantings, the coho became firmly established. By 1970 the sport fishery catch reached ten million pounds. Other species of Pacific salmon - the chinook and kokanee - were also successfully introduced to the Great Lakes area in the late 1960s. To complete their life cycle the salmon return to their home stream to spawn and then die. Millions of salmon are now planted each year. In 1973 the world's largest recorded coho, weighing over thirty-nine pounds, was taken at a state weir.