Baking soda. Wet the area with white glue and water mix (a little liquid detergent also) or mat medium. Sprinkle with the baking soda through a kitchen strainer. After dry, repeat in areas where you want drifts. Keep doing that until you get the effect you are looking for. Be careful to vacuum up any loose baking soda before running your locomotives over it all. If it gets up in the mechanism, it can wreck havoc.
Inexpensive? I used Hydrocal sifted over the scenery, and "snowed" the trees off-layout and installed them after the snow was applied to the ground. The track snow was crushed marble dust from Arizona Rock & Mineral.
Being from northern Wisconsin that does sound and look interesting. Now all I would need would be Snowmobiles. Hehe!
