IF YOU GO

Book the Ski-Free-Stay-Free packages in advance and by specified dates, listed on the website, at www.stayaspensnowmass.com. To talk to a real person call the resort office, at 877-308-8703.

As the thermometer drops in the Roaring Fork Valley, sport shop clerks, restaurant owners and hotel managers in the town of Aspen study the sky, eager for signs of winter. Grey days are promising; black clouds could bring the season’s first big snow.

But there’s blue sky ahead for families planning a ski vacation at one of the “fantastic four” — Snowmass, Buttermilk, Aspen Highlands and Aspen — all within 25 minutes of each other. That’s because the ski group is offering one of the most generous “Kids Stay and Ski Free” packages we’ve seen, the answer for parents who can afford a ski vacation for two or maybe three skiers, but not for four or five.

Free ski play for preschoolers, the 5 and under bunch, is more popular now than ever before. But the Aspen-Snowmass program is for children ages 7-12, those critical years when kids are strong enough to ski, learn fast and aren’t afraid of taking a tumble. And as any ski instructor will tell you, the 7-year-old who loves snow-plowing on the bunny slopes will be skiing intermediate runs next year and flying off the top by the time he or she is 10.

Here’s how the “Kids Stay and Ski Free” package works. For every adult who buys a three, four or five-night lodging-and-lift ticket package (or more days if you have the time) one child gets the same package free, plus one group lesson. If the adult rents skis and boots, the child gets ski gear, too. The child must be sharing a room with an adult and there are some date restrictions.

Do the math. Four can ski for the price of two, six for the price of three, eight for the price of four, and so on. The adults in your group can be grandparents, aunts, uncles or friends; the kids can be your kids or anyone’s kids, as long as they’re 7-12 years old. Especially sweet are this season’s available travel dates, the last two weeks of March and the first week of April, when things warm up a little (January is too cold).

With 3,332 skiable acres, Snowmass isn’t the biggest in North America. But it’s still a giant. With 94 trails and 21 chairlifts spread over four separate summits, the slopes are rarely crowded. You can ski from the summit, in the clouds at 12,510 feet, down to Snowmass Village on trails that fit your skills, from steeps and glades to bump runs, and from open bowls to cruisers and bunny hills.