Once the snow starts piling up in late December, it’s easy to strap on skis at East Glacier [1] and glide to Two Medicine Lake [2]. On nice days it’s an easy day trip.
Links:
[1] http://www.moon.com/destinations/montana/glacier-national-park/east-glacier-and-vicinity
[2] http://www.moon.com/destinations/montana/glacier-national-park/east-glacier-and-vicinity/two-medicine