This area serves as a snowmobile trail in the winter. There are several places like this in town. There is really no way to bike this area, and it's not very nice walking surface. But in the winter, it is a great place for snowmobiles to make their way through town without being on the surface streets.
This sign is provided to post information that snowmobilers may need as they enter town. There are a few of these around, but in the summer, they kind of just blend into the background.