Not a snow mobile, but a skid steer with chains. Summer storage in a pole barn with a dirt floor, winter in the garage, concrete floor. I used 2 sheets of 1/4” OSB. Cut em into 24” strips, 4 six footers, and 2 four footers. The 4’ strips I use at the entrance over the door lip, and slide em in after the machine is in. End of winter, just stack the OSB strips off to the side. Been using the same ones for more than 5 years, the 4’ pieces are getting beat up where the machine drops off the concrete onto the gravel drive.