Aspen or Boulder?

Neither town is a beach destination, so treat swimming as an extra. In Aspen that means rafting the Roaring Fork or a bracing dip in an alpine lake that stays cold even in July. Boulder's version is gentler: the reservoir has a small sandy swim area, and floating Boulder Creek on an inner tube is a warm-weather ritual in town.

Both eat well above their size, but the styles are different. Aspen's downtown grid is built for wealthy visitors: chef-led dining rooms, steak and sushi, serious wine lists and slopeside après-ski terraces, with the Food & Wine Classic every June. The catch is that many kitchens close in the quiet spring and autumn weeks.

Boulder is healthier and more casual. Expect farm-to-table menus, plenty of vegetarian cooking, bakeries, coffee roasters and taprooms across the east side, with the creekside farmers' market and the carved Dushanbe Teahouse as highlights. For fine dining, Aspen has more rooms. For a relaxed lunch and a craft beer, Boulder does it better.

Neither town has major museums, and each fills an afternoon or a day. Aspen's appeal is its silver-boom past: red-brick Victorian blocks around the Wheeler Opera House, painted miners' cottages in the West End and the Ashcroft ghost town up the valley, plus Herbert Bayer's modernist Aspen Institute campus.

Boulder's interest is in campus and science. The 1898 Chautauqua colony sits beneath the Flatirons, the university has sandstone walls and red-tile roofs, and I.M. Pei's atmospheric research laboratory stands on the mesa. Aspen is the place for mining history, Boulder for architecture and ideas.

Aspen has a little more going on after dark, but only in winter. In ski season, après-ski moves from the slopeside decks to hotel bars and a few small clubs, busiest around Christmas, New Year and the X Games, with a well-dressed crowd. In spring and autumn the town goes very quiet.

Boulder runs on taprooms, cocktail bars around Pearl Street and loud student bars on University Hill during term. Nights end early because the trailheads call at dawn. For a big night out, the answer is a 40-minute trip to Denver.

Both are outstanding outdoors bases, and the difference is the type of terrain. Aspen is true high country: four ski mountains in winter, then the Maroon Bells, wilderness passes and summits above 4,000m in summer, with Independence Pass and the Roaring Fork for rafting and fly-fishing.

Boulder sits lower, in the foothills. Over 200km of trails climb from the edge of town onto the Flatirons and mesas, Eldorado Canyon is a world-class climbing wall, and cyclists train on the canyon roads. Rocky Mountain National Park is an hour away. Boulder also has the milder winters for walking, while Aspen has the skiing and the higher, wilder peaks.

Boulder has far more within reach, mainly because Denver is only 40 minutes away by express bus, with its art museum, state capitol and Union Station. A car opens up Golden, Fort Collins, Estes Park and the Victorian mining towns of Georgetown and Idaho Springs.

From Aspen the choice is smaller: Glenwood Springs, Carbondale, the quarry village of Marble and Redstone's coke ovens. In summer you can also cross Independence Pass to Leadville. The pass closes in winter, so in ski season the options get noticeably shorter.

Both work well with children, but for different trips. Aspen is the one for a family ski week, with gentle terrain and kids' areas at Buttermilk and Snowmass and alpine coasters in summer. Its altitude of about 2,400m can leave young children tired for the first day or two, though.

Boulder sits lower and suits a summer week. Children can go tubing on the creek, swim at the reservoir, watch the Pearl Street street performers and visit the university planetarium. Denver's zoo and aquarium are within easy reach, which Aspen cannot offer.

Aspen is easier to manage without a car. The downtown grid takes minutes to cross, the gondola leaves from its edge, free buses run to all four ski mountains, a shuttle goes to the Maroon Bells, and the airport is just outside town. Since most of what visitors come for is in the valley, this covers nearly everything.

Boulder is excellent within town, with creekside bike paths, bike share and buses linking downtown, the campus and Chautauqua. The trailheads beyond the city, Eldorado Canyon and the national park mostly need a car, so outdoor visitors usually hire one.

For a shopping trip, Aspen is the clear pick, as long as you are after luxury. A few downtown blocks hold international designer boutiques, high-end ski wear, jewellers, Western leather and a cluster of art galleries, and window-shopping in the pedestrian malls is part of an evening out.

Boulder's Pearl Street Mall is more modest and more independent, with bookshops, toy shops and boutiques. Its real strength is outdoor gear: climbing, running and cycling shops are excellent for a town of its size.

Neither is cheap, but Boulder is clearly easier on the wallet. Aspen is one of the most expensive places to vacation anywhere, with lift tickets, ski school, rooms and drinks all priced for a very wealthy crowd. Even staying down the valley in Glenwood Springs only softens the bill.

Boulder's hotels are pricey, especially in summer and on university weekends. The trails cost almost nothing, though, buses are affordable, and staying in Denver is an easy way to save.

Aspen packs its music into one summer: an eight-week festival of orchestral, chamber and opera performances, which you can hear for free from the lawn outside the Benedict Music Tent. The Aspen Santa Fe Ballet adds dance, and the Wheeler Opera House keeps concerts and film going for the rest of the year.

Boulder spreads its live music across the year, with rock, bluegrass and roots acts in small rooms downtown and on the Hill most nights. In summer there are orchestral concerts in the 1898 Chautauqua Auditorium and outdoor Shakespeare on campus, and Red Rocks Amphitheatre is about 45 minutes away.

Aspen does relaxation the resort way. Its big hotels have spas with massages and altitude-recovery treatments, the mineral pools and cave vapour baths of Glenwood Springs are an hour down the valley, and Conundrum Hot Springs rewards a long hike. Peak ski weeks are noticeably less calm.

In Boulder, the calm comes from daily life rather than the water. Yoga and meditation studios, acupuncture and a Buddhist-inspired university set the tone, and slow, sunny mornings are the local habit. For a soak there is the modest spring-fed pool at Eldorado Springs, or the hot springs at Idaho Springs, about an hour away.