Act locally, think globally, and carry out what you carry in. Find a trash container for all your litter (including cigarette butts; it's very bad form to throw them out of your car window or to use the beach as an ashtray). Observe KAPU (taboo) and NO TRESPASSING signs. Don't climb on ancient Hawaiian heiau (temple) walls or carry home rocks, all of which belong to the Hawaiian volcano goddess Pele. Some say it's just a silly superstition, but each year, the national and state park services get boxes of lava rocks in the mail that have been sent back to Hawaii by visitors who've experienced unusually bad luck.
Hiking in Hawaii is a breathtaking experience. The islands have hundreds of miles of trails, many of which reward you with a hidden beach, a private waterfall, an Eden-like valley, or simply an unforgettable view. However, rock climbers are, sadly, out of luck: Most of Hawaii's volcanic cliffs are too steep and too brittle to scale.
Hawaiian Trail and Mountain Club, P.O. Box 2238, Honolulu, HI 96804, offers an information packet on hiking and camping in Hawaii; to receive a copy, send $2 and a legal-size, self-addressed, stamped envelope. Hawaii Geographic Maps and Books, 49 S. Hotel St., Honolulu, HI 96813 (tel. 800/538-3950 or 808/538-3952), offers a Hiking/Camping Information Packet for $7. Also note that the Hawaii State Department of Land and Natural Resources, 1151 Punchbowl St., no. 131, Honolulu, HI 96809 (tel. 808/587-0300; www.hawaii.gov), will send you free topographical trail maps.
The Nature Conservancy of Hawaii (tel. 808/537-4508 on Oahu, 808/572-7849 on Maui, 808/553-5236 on Molokai; www.tnc.org/hawaii) and the Hawaii Chapter of the Sierra Club, P.O. Box 2577, Honolulu, HI 96803 (tel. 808/538-6616) both offer guided hikes in preserves and special areas during the year. Also see the individual island chapters for complete details on the best hikes for all ability levels.
Before you set out on the trail, see the "Health & Safety" section, for tips on hiking safety, as well as "What to Pack".