Primarily but not exclusively oriented toward cyclists, Backroads (801 Cedar St., Berkeley, CA 94710, tel. 510/527-1555 or 800/462-2848, www.backroads.com) offers a nine-day “Chile & Argentina Biking” excursion in the Chilean and Argentine lake district around Puerto Varas, and Argentina’s Bariloche and San Martín de los Andes for US$4,498 per person. Its 10-day “Patagonian Walking and Hiking” trip stays at luxury lodgings in Parque Nacional Torres del Paine and Argentina’s Parque Nacional Los Glaciares; rates are US$6,498 per person; a similar trip uses less opulent accommodations for US$4,298 per person.

Bio Bio Expeditions (P.O. Box 2028, Truckee, CA 96160, tel. 800/246-7238, fax 530/550-9670, www.bbxrafting.com) offers weeklong trips from Puerto Montt to its Río Futaleufú base camp for kayaking and multisport trips (US$2,600 pp).

Based at its own deluxe camp, Earth River Expeditions (180 Towpath Rd., Accord, NY 12404, tel. 845/626-2665 or 800/643-2784, fax 845/626-4423, www.earthriver.com) offers 10-day rafting and kayaking trips on and around the Río Futaleufú for about US$3,000 from Puerto Montt.

The Earthwatch Institute (3 Clocktower Pl., Maynard, MA 01754, tel. 800/776-0188, fax 978/461-2332, www.earthwatch.org) arranges a variety of volunteer programs in which participants pay for the privilege of assisting university faculty and independent researchers in archaeological, environmental, or similar projects. Chilean projects have included Easter Island archaeological digs, Río Toltén river otters, and huemul (Andean deer) in the Aisén region.

For travelers at least 55 years old, Elderhostel (11 Avenue de Lafayette, Boston, MA 02111, tel. 877/426-8056, www.elderhostel.org) operates theme-oriented trips that range from relatively sedentary (Wines and Traditions of Chile and Argentina) to active (Energizing Bodies and Minds in Chile’s Lake District), as well as sailing northern Chilean Patagonia’s fjords. Most fall into the US$3,500–4,700 range.

A pioneer on the Río Futaleufú, former U.S. Olympian Chris Spelius’s Expediciones Chile (P.O. Box 752, Sun Valley, ID 83353, tel. 888/488-9082, www.exchile.com) has its own sprawling and secluded camp on the river’s south bank. While they specialize in kayaking the Fu, they also offer rafting and multi-sport holidays that include birding, hiking, and horseback riding. Weeklong stays (US$2,995) include plenty of time and instruction on the river, and transportation from Chaitén; there are also four-day programs at lower prices.

Far Horizons Archaeological and Cultural Trips (P.O. Box 2546, San Anselmo, CA 94979, tel. 800/552-4575, www.farhorizon.com) offers archaeologically oriented trips, guided by top academics, to Rapa Nui (Easter Island) and the Atacama Desert. Fourteen-day trips to Easter Island and the Atacama cost US$6,795 per person double occupancy, not including international airfares.

Mountain Travel Sobek (1266 66th St., Emeryville, CA 94608, tel. 888/687-6235, www.mtsobek.com) does a 13-day “Trekking the Paine Circuit” (US$3,990 pp) and an 11-day “Futaleufú River Adventure” (US$2,590 pp), which can include rafting, sea kayaking, mountain biking, and hiking. The 14-day “Hiker’s Patagonia” (US$4,150 pp) starts in Santiago but flies to Punta Arenas and Parque Nacional Torres del Paine, then crosses the border to Argentina’s Parque Nacional Los Glaciares before finishing with a full day in Buenos Aires. The 15-day “Patagonia Explorer” (US$5,490 pp) follows part of the “Hiker’s Patagonia” itinerary, plus four nights cruising through the Fuegian fjords. Mountain Travel Sobek also has a U.K. contact (67, Verney Avenue, High Wycombe, Bucks HP12 3ND, tel. 44/1494/448901, sales [at] mtsobekeu [dot] com).

Nature Expeditions International (7860 Peters Rd., Suite F-103, Plantation, FL 33324, tel. 954/693-8852 or 800/869-0639, www.naturexp.com) operates “soft adventure” and culture-oriented tours to Argentina and Chile, among other destinations. Their 16-day “Chile: Land of Extremes” (US$5,460) takes in Puerto Varas, Chiloé, Laguna San Rafael, and Torres del Paine, while the 16-day “Chile and Argentina: the Southern Cone” (US$4,425 pp) includes both countries’ northern lake districts, as well as Argentina’s El Calafate and vicinity, and Buenos Aires. The binational, 14-day “Patagonia Wilderness Adventure” (US$4,625 pp) visits Torres del Paine, El Calafate and vicinity, and Buenos Aires.

Fly-fishing specialist Orvis (4200 Route 7A, Manchester Center, VT 05255, tel. 802/362-3750 or 800/547-4322, www.orvis.com) arranges angling holidays in the Andean lake district and the more southerly Aisén region.

Powderquest Tours (7108 Pinetree Rd., Richmond, VA 23229, tel. 804/285-4961 or 888/565-7158, www.powderquest.com) runs five or six ski tours annually. Resorts visited include Portillo, Valle Nevado, Termas de Chillán, and Antillanca; some trips cross to Argentina.

REI Adventures (P.O. Box 1938, Sumner, WA 98390, tel. 800/622-2236, www.rei.com) offers a 12-day “Patagonia Explorer” (US$2,699 pp), focused on Torres del Paine, and a 10-day “Cycle Plus Chile” (US$2,299) in the lake district and Aisén. The 12-day “Northern Lake District” (US$2,599 pp) and the 15-day “Fitzroy & Paine Trek” (US$3,499 pp) also take in parts of Argentina.

Affiliated with the Smithsonian Institution, Smithsonian Journeys (P.O. Box 23293, Washington, DC 20026-3293, tel. 202/357-4700 or 877/338-8687, www.smithsonianjourneys.org) offers a 14-day “Patagonia: Crown Jewel of Chile” excursion (US$5,995 pp) that visits Puerto Varas and vicinity, Punta Arenas, Puerto Natales and vicinity, and Torres del Paine.

Its South American services focus on Buenos Aires and Argentina, but Travel Jewish (P.O. Box 6771, Ithaca, NY 14851, tel. 949/307-9231, www.traveljewish.com) also offers a selection of tours to Santiago, Viña del Mar and Valparaíso, and as far afield as La Serena and Temuco (home to Chile’s oldest synagogue).

Wilderness Travel (1102 9th St., Berkeley, CA 94710, tel. 510/558-2488 or 800/368-2794, www.wildernesstravel.com) offers a selection starting with a 10-day “Torres del Paine” hiking trip (US$3,995) and a nine-day “Futaleufú Adventure” (US$3,095), also primarily a hiking trip. Other trips include the 16-day “In Patagonia” excursion (US$4,795 pp) that focuses mostly on Argentina but also visits Torres del Paine, and a 15-day “Peaks of Patagonia” (US$3,795 pp) that takes in Torres del Paine and Argentina’s Moreno Glacier and Fitz Roy areas.

Wildland Adventures (3516 NE 155th St., Seattle, WA 98155, tel. 800/345-4453, www.wildland.com) operates small group tours (2–8 persons) through locally based guides. The 14-day “In the Wake of Magellan” trip (from US$4,350 pp) includes both Torres del Paine and a segment of the luxury cruise between Punta Arenas and Ushuaia, as well as Argentina’s Moreno Glacier. Other options include the 10-day “Chile Adventure Land of Contrasts” (US$3,175 pp), covering the lake district as well as Torres del Paine; the nine-day “Torres del Paine Base Camp Trek” (US$2,550 pp); and the eight-day “Patagonian Passage” (US$2,650 pp), a sailing trip through the Chiloé archipelago that also visits Parque Pumalín.