indyxcr...since you reg only in WI but ride in IL I'm sure you have a IL drivers license, if that is the case and get stopped you probably will get a ticket. Most likely the local 50 doesn't know but if the DNR catches ya they know the rules. You may say since there is no trail it does not apply but operating a snowmobile anywhere still is under the state laws/regs. I'm like you and register in WI only, but now only ride in WI. On a side note; looks like IL may be going to a trail permit for non-registered sled.
I just got pinched in Oct 2009 from IL for buying an brand new ATV in Twin Lakes WI back in 2005. Well I mail proofed it was registered in WI and stored in WI and never used here. Turns out they wanted the difference in tax that would have come out to approx. $10, not sure if I would have had to pay a penalty on that. But since I had the proof they dropped the claim.
I just got pinched in Oct 2009 from IL for buying an brand new ATV in Twin Lakes WI back in 2005. Well I mail proofed it was registered in WI and stored in WI and never used here. Turns out they wanted the difference in tax that would have come out to approx. $10, not sure if I would have had to pay a penalty on that. But since I had the proof they dropped the claim.