did a little research and found my answer plus something else I was unaware of in 3rd question down taken from the WI snowmobile handbook.
1-
Q Is there an official dates which trails open and close?
A Trail openings and closings are determined at the county level. Landownereasements usually dictate the earliest and latest the trails can openand close. Normally, these easements run from December 1st throughMarch 31st. Each county usually has a “trail hotline” number that providesthe most recent status of their trails.
2-
Q I know I can ride the ditch, 10 feet from a county or state highway andcompletely off the road along town roads. What if the ditch is to steep ornarrow to ride on, can I then go on the road for a short distance?
A No, you must abide by these distances at all time except when crossinga bridge, culvert or railroad right-of-way and after yielding to all vehiculartraffic first.
3-
Q Can I legally ride the ditch (as described above) when the rest of thetrails are closed? Even if there is a marked trail in the ditch?
A Yes, you may ride the ditch at anytime and even if there is a markedtrail there.