Grooming is essentially a two-step process: redistribution of snow, then tilling. Redistribution is the artful part-it involves pushing snow around the trails strategically using the machine's front blade, stealing from deep spots and adding to bare spots until the trail's evenly covered. Tilling, more banal but equally important, entails combing the bulky piles (at around three mph) until they're smooth and free of "death cookies," or big chunks of icy snow.
A few grooming tips:
>Take snow from the sides of trails. "On some of the trails, when there's a bare spot you can see it from the parking lot," says Blademan. "That's bad." Dirt can be covered with the snow that often piles up where the trail meets the trees.
>Keep an eye on your depth. Blademan knows, for example, that the snow-making hydrants on one run are six feet tall. By estimating how much hydrant is visible, he has an idea how deep the snow is. How does he know when he's dug too deep? "When I scrape up some dirt," he says. "Not that I ever do that."
>To spread snow evenly, Blademan often gathers a heaping blade-full of snow, then drives forward while slowly raising the blade.
>Be careful going straight up or straight down. "Sometimes when I'm going downhill, it's like surfing-I can feel the snow pushing me," Blademan says. "I just ride it out." In attempting to climb a steep trail, a cat driver can end up "making coffins": "You get stuck, and the tracks just spin in place and make two big rectangular holes."
>Let it breathe. "Sometimes you push an area of snow around for a while, then you let it sit for an hour, then you come back and pick around at it again. It's like a pimple." What's the point of the recess? "Snow gets lifeless the more you groom it. So you push it around, then wait for some air to get in between it. If you're lucky, a little snow will fall in the meantime. Even an inch of new snow getting in there can be like a shot of adrenaline for the old stuff."