The thousands of acres of mostly untouched wilderness that have been set aside by this nation are not beyond reach -- even for the meekest of travelers. Many vacationers with few or no outdoor skills have ventured into the wild, and returned safely to tell about it, by joining a guided outing into the remote interior of America's national park and forest lands.

The key to enjoying such a trip, provided you don't mind sleeping in a tent or under the stars, lies in choosing the right organization to lead you into the wilderness. The primary goal of some groups, such as Outward Bound, is self-realization, and their trips can be arduous. Other groups, however, want only to introduce participants to the wilderness while helping them have fun at the same time.

These organizations plan most of their trips with the inexperienced vacationer in mind. Generally there are neither age nor physical limitations: Many trips include older travelers as well as school-age youngsters (accompanied by an adult), and some include travelers with physical disabilities. In most cases you can choose exactly how you want to venture into the wilderness: by foot, horseback, river raft, kayak or canoe.

One good reason for signing up for an escorted trip is safety, especially if you are not experienced in outdoor craft. You should expect to be led by capable guides who won't get lost and who can keep you out of danger. A bonus is in the camaraderie that often develops among participants on such outings. Shared meals and activities make a group trip ideal for single travelers who don't want to camp in the wilds alone.

In choosing the group you'll travel with, cost and a good safety record are important factors. But just as significant is the organization's goals. Some of the most popular groups differ quite dramatically in the focus of their outings. Recognizing the difference could save you from making a mistake that could ruin your vacation.

Escorted adventures into the American wilderness generally fall into three distinct categories:

Trips just for the fun of it.

Trips with a strong educational goal.

Trips of self-realization.

Outward Bound of Greenwich, Conn., the famous outdoor adventure school, falls primarily into the self-realization category, although education and fun also are part of the program. Outward Bound presents its participants with physically arduous challenges as a way of building both individual self-confidence and team spirit. If you weren't adequately prepared for the rigors of its programs, however, you might very well develop a dislike for the wilderness. (See related story, Page E1.)

Definitely in the for-the-fun-of-it category is American Wilderness Experience, a Boulder, Colo., adventure travel firm that has put together a variety of outdoor trips in conjunction with more than 125 private outfitters. Participants can sign up for easy to strenuous outings, and they will be pampered along the way. "We're in the vacation business, not the team-building business," says president David Wiggins. Of course, you should have opportunities to learn elements of camp craft from the outfitters.

Teaching outdoor skills, including such basics as cooking a decent meal over a portable camp stove, is the primary goal of the National Outdoor Leadership School of Lander, Wyo. In particular, the school stresses instruction in camping techniques designed to have minimal impact on the environment. This puts it squarely in the educational category. "Self-confidence is a byproduct," says executive director Jim Ratz.

What these and other organizations have in common is their shared interest in introducing people to America's wilderness areas -- the untouched places that you can't get to by motor vehicle. On some trips, you may be a full day's walk or more from the nearest telephone, TV set or toilet, living much as the early Indians and Pilgrims did.

The trips range in length from a few days to two weeks and more. You can expect to spend the entire time outdoors -- cooking over a portable stove, bathing in streams and lakes and enduring whatever weather occurs, foul or fair. This is the "roughing it" aspect of the wilderness. The compensation is beautiful scenery, unhurried days, quiet nights and, presumably, an appreciation for why preserving the wilderness is important.

The nine organizations that follow represent the diversity of groups offering overnight excursions into the American wilderness. Pick from the first three if your primary goal is having fun, from the next three if you prefer a learning vacation and from the final three if you are interested in a self-realization program.

For the Fun of It

Sierra Club: The Sierra Club's outings probably are the closest you will come to duplicating an informal camping trip that you might organize among your friends. The cost of a week-long getaway also is about the lowest you will be charged by any group.

Each year, the organization, which is prominent in the fight for wilderness conservation, puts together a brochure listing some 350 backpacking, canoeing, rafting and other trips throughout the country. A number of backpacking trips have been scheduled this summer for the California Sierras, including treks through Yosemite National Park and the John Muir Wilderness. They range in difficulty from light (35 miles in four or five days) to strenuous (60 to 70 miles with greater ups and downs).

Most Sierra Club trips are a week long, and each is under the leadership of an experienced Sierra Club member. The guide picks the itinerary and is responsible for purchasing food and organizing the menu. Participants are expected to share in cooking and cleanup chores and to carry part of the food and camp equipment.

Among the trips is a seven-day, 43-mile hike into the Pearl Lake region of the John Muir Wilderness east of Fresno. The route, says the brochure, is through forest and meadows and along the streams of the North Fork of the Kings River. Two layover days will be spent at high country lakes. The trip is rated light to moderate; departure is Sept. 6; and the cost is $275 per person, including all food. Transportation to the trail head near Shaver Lake is additional, although shared rides can be organized. Participants must bring backpack, tent and sleeping bag. Sierra Club provides the cooking equipment.

For information: Sierra Club Outing Department, 730 Polk St., San Francisco, Calif. 94109, (415) 776-2211.

American Wilderness Experience: American Wilderness Experience has assembled a roster of 125 individual outfitters that offer a wide variety of multi-day wilderness trips, including travel by foot, horseback, raft, canoe and wagon train. You show up with a sleeping bag, and the outfitter provides the rest. On some hiking trips, llamas -- one for each participant -- carry the food and camping gear.

Among the options, five-day horseback trips are scheduled weekly this summer into the Gros Ventre range of the Rocky Mountains east of Wyoming's Grand Teton National Park. Participants settle in at a remote base camp and make daily rides from there.

The firm advertises its trips as "the civilized way to rough it." On the Gros Ventre outing, accommodations are in walled tents, and a hot water shower is available. The cost is $595 per person, not including air fare. American Wilderness Experience can handle air arrangements.

For information: American Wilderness Experience, P.O. Box 1486, Boulder, Colo. 80306, 1-800-444-0099 and (303) 494-2992.

Glacier Wilderness Guides: Glacier Wilderness Guides is the only guide firm licensed to offer guided treks into the interior of Montana's mountainous Glacier National Park. Trips lasting three, four or six days depart every Monday from mid-May through mid-September for the back country.

Hikers cover about six to eight miles a day, and camp is usually set up beside a mountain lake or a meadow stream, where fishing is a possibility. Groups are limited to no more than seven participants. The guide prepares all meals, but participants can pitch in. The six-day trip is $390, which includes use of all camping equipment; without equipment, the price is $360.

For information: Glacier Wilderness Guides, Box 535 WP, West Glacier, Mont. 59936, (406) 888-5333.

A Learning Experience

National Outdoor Leadership School: The National Outdoor Leadership School was founded 25 years ago by the former chief instructor for Outward Bound. Its initial purpose was to train instructors in outdoor skills. This is still done in semester-long (95-day) programs. But the school also offers two-week courses to the public, some of them restricted to participants age 25 (sometimes 35) and older. The shorter versions generally are organized around a specific activity such as backpacking, sea kayaking and mountaineering.

On all outings, instruction is provided in wilderness safety, minimum impact camping, environmental awareness, map reading and such outdoor living skills as cooking, baking and proper trail nutrition.

The school does not consider itself a survival school. "We teach people how not to get into a survival situation," says executive director Jim Ratz, "and how comfortable it can be to live in the outdoors."

In a two-week wilderness backpacking course in Wyoming offered Aug. 5 and Aug 19, participants will be instructed in how to travel off trail, navigate with topographic maps, traverse boulder fields and cross rivers. Fly fishing, basic rock climbing, plant identification and animal tracking are also part of the curriculum. Typically, a course has 12 to 16 participants with three or four instructors. The cost is $1,600 per person, not including air fare. Camping gear can be rented.

The school is sometimes compared to Outward Bound. The two share similarities, but they also are quite different. On the Wyoming trek, for example, pack horses will carry much of the camping gear; in Outward Bound, participants carry everything.

For information: National Outdoor Leadership School, P.O. Box AA, Lander, Wyo. 82520, (307) 332-6973.

Hardt School of Wilderness Living and Survival: Now in its second year, the Hardt School of Wilderness Living and Survival provides week-long courses in how to live off the land if, for example, you found yourself stranded in a remote forest area without modern outdoor equipment or a supply of food.

The instructors are Ron and Heather Hardt, who have made wilderness ways a lifestyle at their central Vermont home, which they built with their own hands. "I've done this all my life," says Heather Hardt, an art and music teacher in the non-summer months.

The Hardts teach what she calls "hands-on skills." There are lessons in how to build a shelter from natural materials, weave cordage from nettles, purify water, trap and prepare wild animals for food, find edible wild plants and tan animal hides for clothing.

Two programs are offered: basic and advanced. Completion of the basic course, which is taught on the Hardt property, is a requirement before you can sign up for the advanced course. On the advanced course, you head into the Vermont woods to try your newly acquired survival skills.

A basic course is scheduled for Aug. 13, followed by an advanced course. The cost of the basic course is $525, including all meals and lodging in dorm-type accommodations. The advanced course is $450, with lodging in tents and shelters you build for yourself.

For information: Hardt School of Wilderness Living and Survival, Box 231-A, Salisbury, Vt. 05769, (802) 352-1033.

Boulder Outdoor Survival School: Headquartered in the summer in Utah, the decade-old Boulder Outdoor Survival School offers three programs varying in length from seven to 27 days. Among the participants, says owner David Westcott, are people interested in testing their limits, those who want to enhance their self-sufficiency, and others who adhere to a "back-to-the-land philosophy" and want to acquire skills to practice it. Winter courses are offered in Idaho.

The basic earth skills course features instruction in how to survive in the wilderness for up to 72 hours by identifying edible plants, building a fire without matches and finding adequate shelter. The aboriginal living skills course provides techniques for a life in the wilderness, such as tanning leather for clothing and fashioning weapons to hunt. In both courses, instruction is in the Utah back country, and you sleep in a tent.

A third course is "Walkabouts," which are group ventures into the wilderness for periods of one to three weeks. Instead of a tent and backpack, however, you carry only a blanket and a pocket knife, says Westcott. Seven-day summer programs begin at $425 per person, not including transportation to Utah.

For information: Boulder Outdoor Survival School, P.O. Box 905, Rexburg, Idaho 83440, (208) 356-7446.

Self-Realization

Outward Bound: Outward Bound escorts you into the wilderness with the expressed goal of returning you to civilization as a better person for it. You can anticipate being challenged physically -- arduous hikes with heavy packs are common on backpacking trips. And you may have to face up quickly to such long-held self-doubts as a fear of heights. Rock climbing is a part of most Outward Bound programs, as is a "solo" -- spending one or more days and nights in the wilderness on your own.

One of the largest outdoor adventure schools, Outward Bound annually offers more than 500 courses in 20 states. Last year it enrolled 28,000 students. Programs ranging from three days to four weeks are offered in backpacking, canoeing, sailing, rafting and mountaineering. Outdoor skills are taught, but in addition, says the course catalogue, you will "discover new things about yourself" and "expect more of yourself in the future."

A number of canoe trips of eight or 15 days are scheduled from now into October in the forested north woods of Minnesota along the Canadian border. The cost for eight days is $750 to $800 and for 15 days, $1,000 to $1,075, depending on departure date. The price includes use of all equipment.

For information: Outward Bound, 384 Field Point Rd., Greenwich, Conn. 06830, 1-800-243-8520 or (203) 661-0797.

Outdoor Discoveries: New this summer, Outdoor Discoveries has put together a schedule of backpacking and rock-climbing trips in the Cascade Mountains of Washington designed to provide "challenge" and "self-renewal." These goals are similar to those of Outward Bound -- both seek to build self-confidence through accomplishment -- but the approach of Outdoor Discoveries seems gentler.

I took an Outward Bound backpacking trip last spring, and my impression was that all the participants already had plenty of self-confidence or they wouldn't have signed up for the physical challenges spelled out vividly in the school's brochure. After a phone interview with Bob Stremba, executive director of Outdoor Discoveries, I think his excursions might appeal more to people with less self-confidence at the outset.

Stremba's background is in counseling, and this is reflected in his approach. Imagery is important. Before a rock climb, for example, participants spend time with the instructor visualizing how they might successfully reach the top. They always have the option of not climbing. "No one will get left behind," he says. Evening discussions focus on what participants learned about themselves during the day and how the new knowledge can be applied to everyday life.

Overnight courses range from a weekend to 22 days. A seven-day "Adventure Quest" course, scheduled for Aug. 19, is $520 per person. Participants must provide backpack and sleeping bag, but transportation from Seattle is included.

For information: Outdoor Discoveries, P.O. Box 7687, Tacoma, Wash. 98407, (206) 759-6555.

Wilderness Inquiry: Wilderness Inquiry seeks to organize wilderness trips made up of a diversity of participants -- young and old, the fit and the less fit, the able-bodied and the physically handicapped. "Integrated outdoor adventures," says the nonprofit group, "are a great way for people to learn about each other while they explore some beautiful wilderness areas."

The group offers canoe, rafting and kayaking trips in Wyoming, Montana, Wisconsin, Minnesota, Maine, Florida and in Canada. A seven-day canoe trip along Maine's Allagash River is scheduled for Sept. 15. The cost is $345 per person, which includes use of all camping gear but not transportation to Bangor.

Camp chores are shared, according to spokesman Rob Buffler. Those who aren't physically able, he says, "contribute their personality." All trips are open to anyone using a wheelchair. Wilderness Inquiry trains its own staff, and two guides accompany a group limited to eight participants.

For information: Wilderness Inquiry, 1313 Fifth St. SE, Suite 327, Minneapolis, Minn. 55414, (612) 379-3858.