Did something change in Indiana??? As of last year you only had to have your sled registered and tagged in your Home state if not from there. They didn't even have trail permits. When I opened that link it talks of Registration but not permits???
I know its April 1st for Bayfield County Wisconsin. Realize some snowmobile trails are all-season. For example, the Tri-County Corridor (#2) never closes. Also, if there is snow and it is April, ride the fire roads...they don't close.
I really should clarify....They actually close the end of March and are closed on April 1 in Iron County. Again, it all depends on conditions as to weather or not we continue grooming through the end of March.