As I get older, it becomes harder and harder to find a winter sport that I can participate in, because I don’t dare risk my knees, my hips, my skull, etc. So, when our friends, Keith and Holly Williams from Virginia, suggested a snowmobile outing, it sounded fun and harmless. We met them in Jackson, Wyoming, and headed out for a three-day ride through Yellowstone Park, and then one final day in the Grand Tetons along the Continental Divide. Even though it was 17 below at Flagg Ranch the first morning and 20 below the second morning in West Yellowstone,...