From the Lake County Star May 24, 1940 Edition
1. The big rainbows are the most migratory of any of the three species of trout found in Michigan streams. Upstream migration of large rainbow trout, weighing from three to 10 pounds or more, may begin in late fall and continue until early spring when the principal upstream movement usually occurs. Spawning takes place in late March and April in normal seasons in lower peninsula waters and by the time the trout fishing season opens most of these large fish usually have left the streams and practically non remain during the open season. Rainbow trout, tagged in the Manistee River many miles from its mouth, have been taken a few weeks later in Wisconsin waters, proof of their migratory habits.