The school offers four-day beginner and intermediate seminars year-round. A typical day starts at Turtle Rock in the north end of the park. During a quick 30-minute talk about the equipment, you'll be outfitted with a harness, helmet, and climbing shoes, whose bottoms are made of sticky rubber. Then you'll spend the rest of the morning "bouldering" (climbing, low to the ground, up a large boulder) before tackling a sheet of rock. After your guides delve further into the mechanics of the ropes and the belay (the thing that stops you from falling if you slip off the rock), you will spend the afternoon on the rockface, getting comfortable with hand- and footholds as you climb up and rappel down a 75-foot cliff. By the end of four days, you'll look like SpiderMan as you climb a 100-foot cliff. Cost of the program is $315. Most camping is free in the park, but it's first-come, first-served. You may reserve a site in Indian Cove or Black Rock Campgrounds for $10 a night (800/365-2267).

Scuba diving the Big Island, Hawaii 

Scuba divers who head to Hawaii's Kona Coast have more than 70 sites to choose from. After a 15-minute boat ride from the shores you arrive at Turtle Pinnacle. Here, in 35 to 40 feet of water, you'll be eyeball-to-eyeball with large green sea turtles. At Manta Ray Village, the mantas come out at night to feed on plankton. Another favorite location in the area is Long Lava Tube, where you swim in a 70-foot-long cavelike tunnel that was created by lava flowing into the sea. Inside this tunnel, hundreds of tropical fish delight you with their neon patterns.

Eco-Adventures (800/949-3483, molokai-hawan.com/), regarded by many as the number one outfitter in Hawaii, offers numerous diving packages. Six nights at the Royal Kona Resort in an oceanview room, plus rental car, full buffet breakfasts, two days of two-tank diving, and a one-night dive with the mantas is priced at $695. Skip the rental car and breakfasts, and they'll put you up at Kona Seaside Hotel for $498. You can probably get a discount if you book through the Internet.

Sea kayaking the Barrier Island, Georgia

While many islands off the Atlantic coast continue to build resorts and second homes, Georgia has left its barrier islands pretty much alone. Only four of its dozen islands have been developed. The others are still marsh wetlands and dunes, where giant sea turtles come to lay their eggs and the occasional alligator stumbles though brackish swamp. These countless miles of tidal rivers and coastal waters are a sea kayaker's dream.

Sea Kayak Georgia (888/529-2542, seakayakgeorgia.com/), based on Savannah's Tybee Island, takes kayakers on a three-day trip to Little Tybee and Wassaw Islands, of which the former is a green expanse of tidal marsh and maritime forests in various stages of succession, from hammocks of live and laurel oak to scrubby forests of palm and slash pine, as well as deserted beaches populated only by mink, sea otters, snowy egrets, blue herons, and ospreys. On the paddle over, you'll most likely be accompanied by bottlenose dolphins and diving pelicans. Wassaw Island is a national wildlife refuge open to the public during daylight hours only. The cost of the trip is $360, including all food and camping equipment.

Horseback packing, New Mexico

The half-million-acre Gila Wilderness sits in the southwestern part of New Mexico, near the Arizona border. This is desolate country, where 11,000-foot peaks tower over deeply eroded canyons and hundreds of miles of lonely river. Once infamous for Apache raids on early settlers by the likes of Geronimo, Gila is now known for its large herds of elk, bighorn sheep, black bears, and mountain lions.

The only way to pierce this vast interior is by foot or on horseback. Tom Klumker, owner of San Francisco River Outfitters (505/539-2517, gilanet.com/sfroutfitters), has been leading pack trips into this region for the past 25 years. In the saddle of a strong quarter horse that he supplies, you'll lope through large stretches of ponderosa pines and tall aspen, some as high as 100 feet. In the nighttime, you can soothe your sore bum in a cool river. Five-day trips cost $750. Horses, camping equipment, and hearty steak dinners that could satiate John Wayne are included in the price.

Boston-based writer Stephen Jermanok is a contributing editor at Outdoor Explorer, and author of Frommer's Great Outdoor Guide to New England.