Throughout this guide I recommend outfitters and guides that will help you enjoy the great outdoors in their particular areas. One highly regarded company that offers trips throughout the West, including several areas in Colorado, is the World Outdoors, 2840 Wilderness Place, Ste. F, Boulder, CO 80301 (tel. 800/488-8483 or 303/413-0938; www.theworldoutdoors.com), which leads a variety of hiking and multisport adventures. Most trips are 6 days long and include transportation, lodging, and dining.

Ballooning

You can take a hot-air balloon ride virtually anywhere in the state, but the most awe-inspiring scenery is in the mountains. Hot-air ballooning is expensive, and it's one sport where you don't want to cut corners. Choose an experienced and well-established balloon company and, if you have any qualms, ask about their safety record. And of course, you'll pay the highest rates at resorts.

Bicycling

Road biking is popular throughout Colorado, but especially in Boulder, which has just as many bikes as it has people; in Fort Collins, public buses have bike racks. My favorite city path is the Boulder Creek Path, which meanders through miles of Boulder parklands, with no motor vehicle intrusion of any kind.

Boating

Those who take their powerboats along on their visit to Colorado will find lakes scattered across the state. Most have boat ramps, some have fuel and supplies, and some of the larger lakes offer boat rentals. Popular choices include Bonny Lake near Burlington (known for water-skiing), Lake Pueblo, and Trinidad Lake. Because Colorado has been experiencing drought conditions in recent years, it's a good idea to call ahead to check on water conditions. In several instances, lake levels have dropped well below the boat ramps, leaving boaters literally "high and dry."

Camping

With so many acres of public land, Colorado offers practically unlimited opportunities for camping, especially in the mountains. There are over 400 public campgrounds in the national forests alone, plus sites in Bureau of Land Management areas, national parks, national monuments, and state parks. In addition, most communities have commercially operated campgrounds with RV hookups. If you plan to drive an RV in Colorado, a word of advice: Have the mechanical systems checked out first, as there are some extremely steep grades in the mountains.

One of the best places to camp in the state is Rocky Mountain National Park, but it can be crowded, especially in summer. Visit in late September or early October, if possible. Backpackers will find numerous camping opportunities along the Colorado Trail and in State Forest State Park west of Fort Collins. Mueller State Park, west of Colorado Springs, is tops for RV camping.

The Colorado Directory, Inc., 5101 Pennsylvania Ave., Boulder, CO 80303-2799 (tel. 888/222-4641 or 303/499-9343; www.coloradodirectory.com), publishes a free booklet that describes commercial campgrounds, cabin facilities, and resorts throughout the state. For a free copy of Colorado State Parks, which contains details on the state's 40-plus parks, contact state park offices.

Cattle Drives

As elsewhere in the West, opportunities abound for city slickers to play cowboy by riding and roping cattle on actual drives that last from a day to a week or more. Each drive is different, so ask very specific questions about food, sleeping arrangements, and other conditions before plunking down your money. The best places for joining a drive are Steamboat Springs and Durango, with their beautiful mountain scenery and fun towns -- perfect for relaxing at the end of the trail.

Cross-Country Skiing

Practically every major downhill ski area also offers cross-country skiing, and there are thousands of miles of trails throughout Colorado's national forests -- often over old mining and logging roads -- that are perfect for cross-country skiing. Among top choices are Breckenridge, with trails winding through open meadows and a spruce forest, and the beautiful San Juan Mountains near Durango and Telluride. Information is available from the Colorado Cross Country Ski Association (www.colorado-xc.org) and from the U.S. Forest Service.

Dog Sledding

If your fantasy is to be a Canadian Mountie mushing across the frozen Yukon, save the airfare and head to the mountains of Colorado instead. Dog-sled rides are offered at several ski resorts; at Aspen, dog power takes you far from the crowds into the rugged backcountry; some rides end with a fancy dinner.

Fishing

Many cold-water species of fish live in the state's mountain lakes and streams, including seven kinds of trout (native cutthroat, rainbow, brown, brook, lake, kokanee, and whitefish), walleye, yellow perch, northern pike, tiger muskie, and bluegill. Warm-water sport fish (especially in eastern Colorado and in large rivers) include catfish, crappie, and bass (largemouth, smallmouth, white, and wiper). The best fishing spots are the Arkansas River near Salida, the Roaring Fork River near Aspen, and the numerous streams and lakes in the mountains surrounding Steamboat Springs.

The fishing season is year-round, except in certain specified waters, and licenses are required for all anglers 16 and older. A 1-year license costs $56 for a nonresident and $26 for a resident. A 5-day license for nonresidents costs $21, and 1-day license costs $9 for both residents and nonresidents. The Colorado Division of Wildlife, 6060 Broadway, Denver, CO 80216 (tel. 303/297-1192; www.wildlife.state.co.us), can answer your questions; for a recorded statewide-fishing report, call tel. 303/291-7534.

A Wimpy State Fish -- Mistakenly believed to be extinct in 1937 and listed as an endangered species in the early 1970s, the greenback cutthroat trout has made a comeback, and in 1994 was named the official Colorado State Fish by the state legislature. It replaced the rainbow trout, a California transplant that had been listed on maps and other documents as the state fish, although state Division of Wildlife officials couldn't say why.

Part of the greenback's problem is that it fails to live up to its cutthroat name, letting other trout invade its waters and practically jumping on any hook dropped into the water. But rumors of its demise were premature, and two native populations were discovered just outside Rocky Mountain National Park in 1973. Efforts were begun to reintroduce the fish to its native waters, as government agencies and the conservation group Trout Unlimited provided it with places to live that are free from more aggressive newcomers. By 1978, its status had improved from "endangered" to "threatened." State wildlife officials hope that if the greenback continues to prosper, it can eventually be removed from the "threatened" list.

Today the greenback cutthroat can be found in some four dozen bodies of water around the state, including several lakes in Rocky Mountain National Park. A good place in the national park to see the greenback cutthroat close-up is from the boardwalks through the Beaver Ponds on Trail Ridge Road.

Although the greenback's designation as official state fish does not provide any additional protection, Division of Wildlife officials say it strengthens the public's willingness to protect the fish and encourages anglers to throw it back if they catch it, as should be the rule with any threatened species.

Four-Wheeling

For years, skiers have known that four-wheel-drive vehicles make getting to and from the slopes easier. But SUVs and 4WD trucks are also popular for exploring Colorado's backcountry in summer, especially its miles upon miles of old logging and mining roads. Top locations for four-wheeling include the San Juan Mountains around Ouray and Telluride. You can get information on events and tips on places to go from the Colorado Off Highway Vehicle Coalition, P.O. Box 620523, Littleton, CO 80162 (tel. 303/539-5010; www.cohvco.org).

Golf

Clear blue skies and beautiful scenery are hallmarks of Colorado golf courses, but don't think they're merely pretty faces; these courses can be as challenging as any in the country. Balls travel farther here than at sea level, and golfers tend to tire more quickly, at least until they've adapted to the higher elevation. Be prepared for cool mornings and afternoon thunderstorms even at the height of summer. High-elevation courses, such as those in Steamboat Springs and Vail, are shut down by snow in winter, but those at lower elevations, such as along the western slope, in the southwest corner, and around Denver, are often open year-round.

Good golf resorts can be found in Crested Butte, Winter Park, Pueblo, and Alamosa; for high-altitude putting, try Leadville. For what is probably the best golf resort in the state, go to the Broadmoor in Colorado Springs. For information on the state's major golf courses, check with the Colorado Golf Association, 5990 Greenwood Plaza Blvd., Ste. 130, Greenwood Village, CO 80111 (tel. 800/228-4675 or 303/366-4653; www.cogolf.org). Another information resource is Colorado Golf (www.golfcolorado.com), an annual magazine published jointly by several statewide golf organizations and available free at state welcome centers.

Horseback Riding

It's fun to see the Old West the way 19th-century pioneers did: from a horse's saddle. Plenty of stables and outfitters lead rides lasting from 1 hour to several days, but I recommend those near Estes Park, Steamboat Springs, Grand Junction, Durango, and Telluride. If you'd like to spend your entire vacation on horseback, the Sylvan Dale Guest Ranch (tel. 877/667-3999 or 970/667-3915; www.sylvandale.com) just outside of Loveland is among the best.

Mountain Biking

The town of Crested Butte claims to be the mountain-biking capital of Colorado, but Telluride, Vail, and Durango are also top spots for fat-tire explorations. Those planning to go mountain biking in western Colorado can get current trail information from the Colorado Plateau Mountain-Bike Trail Association, P.O. Box 4602, Grand Junction, CO 81502 (tel. 970/244-8877; www.copmoba.org).

The Colorado Trail is also open to mountain bikers, but they need to detour around six wilderness areas that are closed to all forms of mechanized travel. Riding the entire 500 miles -- it takes at least 4 weeks -- is easily the state's top mountain-bike adventure, but you can join or leave the trail at almost any point. One easily accessible stretch runs 24 miles from Copper Mountain Ski Resort to Tennessee Pass, crossing 12,280-foot Elk Ridge and descending into the ghost town of Camp Hale. On the trail, bikers yield to hikers and equestrians, and detour around designated wilderness areas. Contact the Colorado Trail Foundation.

Rafting & Kayaking

Rivers swollen with melted snow lure rafters and kayakers from spring through midsummer, when rivers are at their fullest. Salida has become a famous rafting center; other popular destinations include Fort Collins, Estes Park, Grand Junction, and Glenwood Springs.

Rivers are classified from Class I to VI, depending on the roughness of their rapids. Class I is an easy float trip, practically calm; Class II has some rapids alternating with calm; Class III has some difficult rapids, with waves and boulders, and can be narrow in spots; Class IV is considered very difficult, with long stretches of rough, raft-flipping rapids; Class V is extremely difficult, with violent rapids and steep drops; and Class VI is considered unrunnable. The Arkansas River near Salida offers a variety of rapids from easy to almost unrunnable, and the Colorado River through Glenwood Canyon is a particularly scenic Class II to III river, wild enough for some thrills but with enough calm stretches to let you catch your breath and enjoy the view.

You'll find a range of trips from numerous reliable outfitters. For a free directory of licensed river outfitters and tips on choosing a rafting company, contact the Colorado River Outfitters Association, P.O. Box 1662, Buena Vista, CO 81211 (tel. 303/229-6075; www.croa.org).

Rock Climbing

Although rock climbing is not as big here as in other parts of the West, Colorado does attract its share of climbers. One of the best spots is the Black Canyon of the Gunnison near Montrose, an extremely narrow chasm that sees little daylight; there are also several good spots near Durango. You can get information from the Colorado Mountain Club, American Mountaineering Center, 710 10th St., #200, Golden, CO 80401 (tel. 303/279-3080; www.cmc.org).

Rockhounding & Gold Panning

The state's mining heritage continues in many areas among rockhounders, who search for semiprecious gemstones, petrified woods, and agatized fossil bones. The Salida area has some of the best rockhounding opportunities in the state, and amateur gold panners should visit Idaho Springs (near Denver), Silverton, and Country Boy Mine in Breckenridge. Contact the Colorado Geological Survey, 1313 Sherman St., Rm. 715, Denver, CO 80203 (tel. 303/866-2611 or 303/866-4762 for publications; www.geosurvey.state.co.us), for information, maps, and a list of locations.

Snowmobiling

If you've never been snowmobiling, the best places for a guided snowmobile tour are Steamboat Springs and Aspen. If you're an experienced snowmobiler and you plan to bring your rig with you, national forest trails are prime snowmobiling spots. Some of the state's best and most scenic rides are in Roosevelt National Forest, about 50 miles west of Fort Collins (via U.S. 287 and Colo. 14) at Chambers Lake. Because many of these trails are multiuse, snowmobilers should watch out for cross-country skiers and snowshoers, and slow down when passing. Colorado's light, dry snow is usually suitable for snowmobiling all winter long, although warm spring days can result in sticky snow, especially at lower elevations, which can gum up the works and make the going rough.

Information on snowmobiling in the state, including current trail conditions, is available online from SledCity (formerly the Colorado Snowmobile Association) at www.coloradosledcity.com. For information on snowmobile regulations, contact Colorado State Parks.

Wildlife- & Bird-Watching

There are numerous locations in Colorado to see animals and birds in the wild, including some that are close to the state's major cities. The South Platte River Greenway near Denver is a good spot to see ducks and other waterfowl, songbirds, deer, and beaver; the Monte Vista and Alamosa national wildlife refuges in the San Luis Valley are some of the best spots in the country to see migratory greater sandhill cranes; and if you head to the prairie in southeastern Colorado, the Comanche National Grasslands is the place to see the rare lesser prairie chicken. Other top spots for wildlife include Durango, Telluride, Winter Park, Vail, Rocky Mountain National Park, and Colorado National Monument.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.