Snowmobiling is big business in Minnesota. About 70 percent of the 200-thousand snowmobiles sold last year were made in Minnesota. The sleds are sleek and fast with hi-tech suspension and built in handwarmers. It's a long ways from the humble roots of the snowmobile industry. Thirty years ago snowmobiles were little more than a motorized metal sled. Those early machines are now in great demand. Collecting and restoring antique snowmobiles is becoming an industry all its own.