A number of nature-oriented tour agencies lead off-the-beaten-track Puerto Vallarta–area excursions. Vallarta Adventures (tel. 322/297-1212, U.S. tel. 888/303-2653, www.vallarta-adventures.com) offers boat tours to the Islas Marietas wildlife sanctuary (sea turtles, manta rays, dolphins, whales, seabirds), a dozen airplane excursions, and a rugged all-day Mercedes-Benz truck ride (canyons, mountains, crystal streams, rustic villages) into the heart of Puerto Vallarta’s backyard mountains.

The offerings of unusually ecologically aware Expediciones Cielo Abierto (Open Sky Expeditions, 339 Guerrero, two blocks north of the riverside Municipal Crafts Market, tel. 322/222-3310, U.S./Can. tel. 866/422-9972, www.vallartawhales.com) include snorkeling around Punta Mita, hiking in the Sierra Cuale foothill jungle, bird-watching, cultural tours, dolphin encounters, and whale-watching.

Viva Tours (tel./fax 322/224-0410, www.vivatours-vallarta.com) organizes a number of off-the-beaten-track adventures, including horseback riding, hiking, biking, fishing, and much more.

Finally, if you want to see a listing of all adventures possible in Puerto Vallarta, visit www.puertovallartatours.net, the creation of web-savvy agents John and Sandra, who offer a long list of options, from booze cruises and golf to visits to remote Huichol mountain villages and hot-air ballooning.