It's crazy - there's a whole other highway system in the winter for snowmobiles. Like, they actually have a for reals Provincial highway sign with a number and everything. It cuts right across lakes. And they have markers to mark the two "lanes" for coming and going snowmobiles.
UPDATE! On today's walk, there were many signs of this being a non-pedestrian-friendly zone: speed signs, road directions, and lots of skidoo marks. And then, when I heard a snow mobile approaching, I stepped off to the side where my left leg was INSTANTLY submerged up to my crotch (would have been deeper if not for said crotch). It was STUCK, no wiggling out. I tried to look cool while the snowmobiler passed me then frantically dug myself out with my two hands and turned my damp self back in the direction of home. Sigh.