Glacier offers every kind of backcountry experience, from 1-mile (2km) day hikes to 2-week treks. Consider your fitness level, backcountry experience, and interests, then get some advice from one of the visitor center rangers. They can provide you with area maps, but a topographical map is highly recommended if you're going for more than a short walk.
Backcountry campgrounds have maps at the entrance to show you the location of each campground, the pit toilet, food-preparation areas, and, perhaps most important, food-storage areas. If you fish while camping, it's recommended you exercise catch-and-release so as to avoid attracting wildlife in search of food. If you eat the catch, be certain to puncture the air bladder and throw the entrails into deep water at least 200 feet from the nearest campsite or trail. You will need a permit to camp.
Guided Backcountry Trips--Glacier Wilderness Guides (tel. 800/521-7238 or 406/387-5555; fax 406/387-5656; www.glacierguides.com) is the exclusive hiking guide service in the park. They will put together any kind of trip for you, or offer weekly departures for 3-, 4-, and 6-day trips. Prices vary depending on the trip, but you can figure on spending $100 to $120 per person per day. They also rent equipment and provide "Sherpa service," where the guide will carry your gear. The season runs May through September.