Stake out a hot spring:
Mammoth’s volcanic valley floor is peppered with natural hot springs where you soak in a big steamy tub with mountain panoramas as your backdrop. To find Hilltop Hot Tub, head east on Benton Crossing Road (look for the funky green church). After the third cattle crossing, around 3 miles later, pull over and look for the trail crossing the snowy meadow to the tub in the distance.
Hike in the snow: Tamarack’s full-moon snowshoe (Jan 17–19) is a chance to get the particular thrill of tromping around in the wild at night. Dessert and hot toddies served by the fire when you’re back. Through Mar; $40; tamaracklodge.com.
Run with the dogs: Head out with a musher and a pack of huskies for 50 minutes of sledding with Mammoth Dog Teams ($90; mammothdogteams.com).
Hit the sledding hill: There are several sledding spots, but for tube rentals and the bonus of a rope tow, try Sledz (tubes $25; on Minaret Rd. near the Main Lodge; 760/934-7533).