Actually it's very easy to know, and I would expect your DNR fisheries people do know. If the springs are cold; and archeological escavations of pre-European settlements yield trout bones, or early settlers recorded catching "specled" trout in the streams, then there were trout. If the springs are still cold, then trout can be re-introduced. But if there are no cold springs, or never were, then trout will never live there.Originally Posted by Bear742