Palm Desert or Sun Valley?

Neither place has a beach, so the difference is the kind of water you get. Palm Desert's swimming is all in heated resort pools, and the Pacific is two hours away over the mountains.

In Sun Valley you can swim outdoors in July and August at Redfish Lake, which has a sandy shore below the Sawtooths but cold water. For the rest of the year, the heated outdoor pools are the only reliable place to swim.

The two are broadly level, and both offer resort-town eating rather than a food destination. Palm Desert's El Paseo steakhouses and patio bistros suit a warm evening outdoors. The valley also has two things Sun Valley lacks: the date shakes and Mexican taquerias around Indio, and Palm Springs close by for more variety.

Ketchum's restaurants lean towards mountain fare: après-ski grills, and a few ambitious kitchens cooking trout, lamb and elk. Choice there thins out in the quiet spring and autumn weeks.

Neither is a sightseeing destination, but Palm Desert gives you a little more to see. It has the Palm Springs Art Museum branch with its sculpture garden, and the mid-century modern houses of Palm Springs are a short drive away.

Sun Valley's interest is in its story. It was built by the Union Pacific railroad in 1936 as America's first destination ski resort. You can see the photo-lined corridors of the Lodge and Hemingway's grave in Ketchum, and an afternoon covers it all.

Both are early-to-bed places, but the desert gives you more options for a late night. The patios on El Paseo close early. After that, the tribal casinos keep their lounges open into the small hours, and downtown Palm Springs has the valley's liveliest bars and a well-known gay scene.

Going out in Sun Valley means après-ski in Ketchum's saloons and wine bars, with perhaps a band on a winter weekend. Outside the ski season and midsummer, the town is quiet soon after dinner.

Sun Valley is the stronger outdoor destination, and it stays active all year. In winter you have steep, long runs on Bald Mountain, Nordic trails and backcountry touring. In summer there is mountain biking, fly fishing, rafting on the Salmon River and alpine lakes in the Sawtooths.

Palm Desert's landscape is a real draw in its own way. It has the Santa Rosa trails, fan-palm oases in the Indian Canyons, the granite boulders of Joshua Tree and plenty of golf. However, the summer heat confines all of it to dawn for four months of the year.

Palm Desert has far more places to visit on a day out. Palm Springs is twenty minutes away, and Temecula's tasting rooms, the mountain village of Idyllwild, the Pioneertown film set and the painted hillside of Salvation Mountain are all within reach.

Sun Valley's surroundings are wild country rather than places to visit. Hailey's main street, the log-cabin outpost of Stanley and Shoshone Falls, two hours south, are the options, and most days out from Sun Valley head into the mountains instead.

Palm Desert is easier with children who don't ski. The Living Desert's giraffes and cheetahs fill a morning, and the Palm Springs tramway is a hit with older children. Resort pools with slides keep everyone busy in between, as long as you avoid the midday heat in summer.

Sun Valley suits families who ski or love being outdoors. It has a gentle beginners' hill away from the main mountain, a well-run ski school, and horse rides and an outdoor ice rink in summer. Toddlers may struggle with the altitude and the cold, and teenagers who don't ski may find it quiet.

Sun Valley is the easier base without a car. Ketchum's flat grid is walkable, a free bus links the town, the village and the lift bases, and a paved path runs down the valley. You still need to drive to reach the Sawtooths or the trailheads.

Palm Desert is built for the car, with resorts and shopping centres spread along wide boulevards. Only a few blocks of El Paseo are pleasant to walk. On the plus side, the roads are uncongested and parking is easy.

Palm Desert offers far more shopping. El Paseo's palm-lined boutiques, jewellers and galleries make browsing a social outing. On top of that there is an indoor mall, a big designer outlet centre half an hour west, and the vintage and mid-century furniture shops of Palm Springs.

Ketchum's few blocks are narrower and pricier. What they do well is ski and fly-fishing gear, western art galleries and cashmere for second-home owners.

Palm Desert is the cheaper of the two, though neither is a bargain, and its costs pile up in different places. You will almost certainly need a hire car, which adds a steady daily sum, and meals carry US prices plus tips. Golf rounds and spa treatments are where a budget drains fastest. Rooms are dearest in the winter and spring high season, especially around the big valley events.

Sun Valley costs more at every turn, but a ski week there can be done without a car, because the free bus links Ketchum, the village and the lift bases. Most of the money goes on lift access and on rooms during peak ski weeks and midsummer. The quiet spring and autumn months are the least expensive time to come, although some kitchens shorten their hours then.

Palm Desert has more to offer, and most of it comes in winter. The McCallum Theatre brings touring Broadway shows, ballet and orchestras, the casinos host big-name concerts, and Coachella and Stagecoach fill a few spring weekends in Indio.

Sun Valley's season is summer. The Sun Valley Music Festival puts a professional orchestra in the pavilion by the lodge, and skaters perform on the outdoor rink in the evenings. The rest of the year there is very little.

For a vacation spent unwinding, Palm Desert has the edge over Sun Valley, because in the desert rest is the whole point of the place and not just the end of an active day. The days follow an unhurried rhythm of golf, late breakfasts and early nights. The dry, sunny winter does much of the work, and you spend it soaking and dozing in warm sunshine.

In Sun Valley the calm comes once the lifts close, after a day of effort on the hill or the trail. The best of it is a steaming outdoor pool with snow falling around you, or a soak in the cold mountain air of the Warm Springs valley. It is restful, but there is no bathing tradition here to plan a stay around.