Spawning commences in the mid 40's, but they will keep going once they start, even if it gets colder. When the flow gets up there, there may be spots on the bottom that are still sheltered enough for them. Suffice it to say that the species did OK before hatcheries in their native range, and some of those rivers make the SR look like a short ditch. And, late as it is, there could still be freshies after this goes down, I know people that have caught bright finger lakes spawners in June.
L13