I was in OH with VC last week and the group camped across from us hunted Turkeys to noon (end of shooting hours) and picked mushrooms in the afternoon.
The four guys picked 1200 mushroms in about 4 afternoons. All morels. All on public land and most of them very large.
The lilac were just blooming and the aspen/poplars just let loose with the cotton.
I figure that time climate wise is about Mothers day and the week following here in WI.