Denver or Rapid City?

Neither city is a place to swim, but Rapid City makes slightly more of it. Sylvan Lake, Sheridan Lake and Pactola Reservoir sit among the pines within half an hour and are warm enough for a pleasant dip in high summer.

Denver's nearest swimming is at the reservoir beaches of Cherry Creek and Chatfield on the edge of the city, which feel more like a suburban outing than scenery. A hotel or public pool is the likelier way to cool off there.

Denver gives you far more to eat. Its beer culture runs from the warehouse taprooms of RiNo to the streets around Coors Field, green chile turns up on almost everything, and the Vietnamese and Mexican kitchens along Federal Boulevard give it a range Rapid City cannot match.

Rapid City's food is hearty Great Plains fare: steakhouses, bison, chislic and Indian tacos on Lakota fry bread, plus a handful of brewpubs on Main Street. The last two are worth trying once. Beyond downtown, though, it is mostly chains and fudge shops.

Denver has the deeper list of sights. Around Civic Center Park are the Denver Art Museum with its Native American collection, the Clyfford Still Museum and the gold-domed Capitol, and the brick warehouses of LoDo and Larimer Square add the old commercial city. Together they fill two or three days.

Rapid City's own sights take a day at most. There are the bronze presidents on the downtown street corners, the Journey Museum on Lakota and Black Hills history, and Badlands fossils at the School of Mines. Its famous landmarks are all out in the hills.

Denver is the clear choice for evenings out. Cocktail bars in RiNo, sports crowds in LoDo on game nights and the dive bars of East Colfax make for quite different nights, even though it remains a city of bars rather than clubs.

Going out in Rapid City means a few blocks around Main Street Square, with brewpubs and country-music bars that mostly empty well before midnight. Only the week of the Sturgis rally in August makes the region loud and late.

Both are excellent outdoor bases, and the difference is in kind. Denver faces the high Rockies, with summits over 4,000m, alpine tundra in Rocky Mountain National Park and big ski resorts along I-70 in winter. The catch is that thin air and long drives make you work for it.

Rapid City's Black Hills are lower and gentler but pack more variety into a day: granite spires on the Needles Highway, bison herds in Custer State Park, two long cave systems underground and the eroded Badlands an hour to the east. Skiing there is limited to a small area near Lead, so winter sports favour Denver.

The two are close here, but the outings differ. From Rapid City you head for landmarks: Mount Rushmore within half an hour, the Crazy Horse Memorial and its museum, the gold-rush streets of Deadwood and the mammoth bones at Hot Springs.

From Denver you visit towns rather than monuments. Boulder sits under the Flatirons, Georgetown has its Victorian mining streets and narrow-gauge railway, and Manitou Springs and Estes Park lie further out. From either city you will need a car.

Both work well with children, and the difference is in how the days run. Denver keeps a lot inside the city: the zoo and the dinosaurs of the Museum of Nature & Science share City Park, and the Children's Museum, an aquarium and an amusement park are grouped by the South Platte.

Rapid City is the classic family road trip. Children can watch bison stop the traffic, go on cave tours, pan for gold, visit the reptile park and Storybook Island, and end the day at a motel pool. The price is long hours in the car, while in Denver it is the altitude and strong sun you need to watch with small children.

Denver is far easier without a car. The flat downtown is walkable, a free shuttle runs along the 16th Street Mall, a train links the airport to Union Station, and light rail reaches the suburbs. Only the mountains really need a hired car.

In Rapid City a car is all but compulsory. Downtown is small enough to walk, but the city buses do not reach Mount Rushmore or the state parks. On the plus side, traffic is light, parking is easy and the scenic roads are part of the trip.

Denver has more to browse, with the upscale mall and boutique blocks of Cherry Creek, the vintage and record shops of South Broadway, and large flagship stores for outdoor gear. Rapid City's shopping is narrower but distinctly local: Black Hills gold with its grape-leaf designs, and Lakota quillwork, beadwork and star quilts in the downtown galleries. Both are good for Western boots and hats.

Denver has the prices of a large American city. Downtown hotel rates climb when conventions are in town and again through the ski season, sales tax and tipping add to every restaurant bill, and most visitors also pay for a hired car. You can soften this by staying out along the light rail and eating at taquerias and brewery taprooms, and the parks and foothill trails are free.

Rapid City is the cheaper of the two, with motels and casual meals that are reasonable by national standards. Its costs come from different places. A car is a fixed daily expense, with fuel and entry fees for the parks and caves added on top. Prices also jump at set times rather than staying high all year: rooms near the hills fill and rates rise through summer, and in the week of the Sturgis rally rooms for many miles around become very expensive.

Denver wins this easily. A summer show at Red Rocks Amphitheatre, set between its sandstone monoliths, is worth planning a trip around. The Denver Center for the Performing Arts adds resident theatre, touring musicals, the Colorado Symphony, opera and ballet, and Five Points keeps its jazz rooms.

Rapid City has a local symphony, touring shows at the civic centre and summer plays in a playhouse in Custer State Park. Its most distinctive performances are the powwows, above all the large autumn gathering.

Neither city has a bathing tradition of its own, so for hot water you leave town. From Denver, the mineral pools and steam caves of Idaho Springs are under an hour away, there are larger hot-spring resorts deeper in the mountains, and the city has more day spas and yoga studios.

From Rapid City, the historic spring-fed pool at Hot Springs is an hour south. Beyond that, relaxing there mostly means a quiet cabin in the pines.