"On my 40th birthday," my friend Jo said, "I want to be at the Grand Canyon."

It was, in fact, my 40th birthday, and we were standing on top of Mount Snowdon in Wales.

But seven years later, it was Jo's 40th and we were sitting on the very edge of the Grand Canyon, sipping champagne and watching the setting sun draw the curtain of night over the still and profound rock before us.

I'd driven from Virginia to the Grand Canyon with my family. Jo had flown in from London to Las Vegas, then driven the 263 miles to the canyon's North Rim with her companion, Alan, and another friend, Jen, whose 40th birthday we'd celebrated four years previously by hiking in northern England.

We reunited on the porch of Jo's cabin, No. 306, at the Grand Canyon Lodge--one of the four coveted Rim Cabins that have magnificent views into the canyon. Cabin 305 was my family's. We had, as is necessary, booked them two years in advance, the earliest you can book a reservation, although only six months is usually required to secure any of the other 165 cabin rooms.

Our cabins, made of local stone and log, were clustered like a tent encampment, and connected to one another and the main lodge with winding concrete trails. We settled into the cushioned, wrought-iron porch chairs and looked out at a full panorama of the canyon, whose sides began sloping away right off the edge of the porch. Some 20 feet down, a concrete walking trail--the popular quarter-mile path out to Bright Angel Point from the lodge--bisected the drop before it continued precipitously on.

We were at the North Rim for the simple reason that most people who visit the Grand Canyon go to the South Rim. But while the North Rim traditionally gets only 10 percent--around 800 cars a day--of the 4 1/2 million people who visit the Grand Canyon National Park annually, this number is increasing dramatically. According to the Guide, a park publication, the North Rim is "on the cusp of change." Its 400,000 visitors this year is expected to increase to 1 million by 2010.

In other words, go now.

Due to its remote position and a border dispute with Utah, the North Rim was isolated and undeveloped well into the 20th century. When the South Rim's grand El Tovar Hotel opened (it's now one of the canyon's seven lodges) in 1905, tourists poured in, but the North Rim was still accessible only by crude dirt roads.

In 1928, in an attempt to draw some of the booming tourist trade away from the Sante Fe Railway feeding into the South Rim, the Union Pacific Railway constructed the Grand Canyon Lodge. Gilbert Stanley Underwood was the architect for all the Union Pacific lodges, refining his rustic architectural style as he went along, using local stone and wood for construction and drawing heavily on the arts and crafts movement of the time. (His piece de resistance is the Ahwahnee Hotel at Yosemite National Park.)

When the Grand Canyon Lodge opened almost 70 years ago, it could accommodate 250 guests--half of what it can today. A Union Pacific brochure from those early days said the lodge "harmonizes perfectly with its sublime surroundings and seems itself a work of nature." And so it does. Though it burned down in 1932, it was rebuilt two years later on the remaining stone foundation and retains that organic appeal as if it magically sprang up from the earth overnight.

The beams in the two-story, 50-foot-wide dining room are, for example, tree trunks--great round tree trunks from the huge ponderosa pines that once stood near the spot. The stone foundation is made from the same 250-million-year-old Kaibab limestone that makes up the rim of the canyon, limestone shot through with the accumulated remains of the plants and animals that once inhabited the shallow, warm sea that covered this area. The segmented fossils of crinoids, a plantlike animal of this ancient sea, abound in the rock.

I'd come to the Grand Canyon Lodge and the North Rim four years earlier, quite by chance, at the recommendation of another friend, who has traveled the world over many times. "It's very different from the South Rim," he'd said. "Not nearly so touristy. And a lot more difficult to get to. But well worth it."

I'd been to the South Rim too, some 16 years before. In February (because of snow, the North Rim is closed to all but cross-country skiers and snowshoers from around mid-October to mid-May), when it was decidedly non-touristy. With great anticipation I'd driven in, parked with the handful of other cars, then made my way to the rim, heart pounding.

"Where is it?" I said, peering into the white cloud swirling at my feet. Had I driven all this way for nothing? Where was it?

And then the cloud parted and I glimpsed, as it seemed to me then, part of the Earth's soul--ragged slices of pink and brown and beige and red rock, layered in a 2 billion-year time line of Earth's geologic history, descending chronologically down the almost impossibly deep gash in the Earth's surface, like ancestral portraits down a long, steep staircase. At the bottom, 4,860 feet below, was the Colorado River, glistening like a slug's trail--part of the 277 miles of the river's total 1,400-mile length that are within Grand Canyon National Park.

Then the cloud moved back in and all I saw was white. But that vignette was burned into my brain like acid into metal. I had to go back and see more; it became my quest. So, when my friend told me about the Grand Canyon Lodge on the North Rim, off we went in the summer of 1995. I'd heard about the hordes who were pouring into the South Rim and grossly overloading its facilities, of people sitting in lines of traffic for hours.

But for the auspicious recommendation of my friend, my family and I would have been part of that madness. Instead, we approached the North Rim over almost deserted roads. At Jacob's Creek, we turned south on state Route 67 for the last 45 miles to the North Rim, leaving the arid desert lands of northern Arizona for the lush meadows and forests of the Kaibab Plateau, pushed up to heights of 7,000 to 9,000 feet above sea level by forces deep within the Earth some 65 million years ago.

At this height, the plateau has a completely different climate than the adjacent desert lands and can get up to 150 inches of snow in winter. In the spring, its melt water rushes off the south-tipped plateau, helping to carve the numerous deep-sided gorges and canyons that characterize this northern section of the park and keep the North Rim so much farther back from the Colorado River than the South Rim that looms right over it.

Seven hundred years ago, a small band of Paiute Indians lived a simple existence as hunters and gatherers on these sub-alpine meadows that flanked the two-lane road we traveled and that, in springtime, sway with the heavy bloom of wildflowers. Kaibab comes from two old Paiute words meaning "mountain lying down."

When John Wesley Powell, the first person to navigate and conduct a scientific study of the entire Colorado River, came across the Paiutes in 1869, there were about 500; now half that number live on the Kaibab Paiute Indian Reservation between Fredonia and Colorado City, west of Jacob Creek. Many were pushed out by the ranchers who ran large herds of cattle and sheep on the plateau in the late 1800s. When the Grand Canyon Game Preserve was established in 1906, though, the meadows were depleted from overgrazing and most of the ranchers gone.

As we drove through late in the day, the shadows of aspens and ponderosas edging the meadow in a ragged frill, a coyote loped through, paused when we did, eyed us momentarily, then continued into the woods. Farther along, a deer bounded across the sward, leaping high over the grasses in balletic splendor.

The spruce and fir interspersed with the aspen and pine in the highest elevations of the woods here are remnants of the forest that dominated the plateau 20,000 years ago. For 10,000 years, during the last major ice age, when the climate was cooler and more moist, spruce and fir proliferated, their growth extending almost to the bottom of the canyon.

Then the ice began to retreat and the world warmed up and the spruce and fir, except in the pockets of highest elevation on the plateau, died out. Today the survivors make up the largest stand of these trees in Arizona.

Twelve miles north of the North Rim, we paid our $20 to enter Grand Canyon National Park (good for seven days on either rim) and, some 10 miles farther on, began to catch glimpses of the canyon through the trees, then cabins tucked in beneath their boughs. Finally the road ended at the rustic beauty of the lodge, all wood and stone and ambling people.

The view within stopped me cold. Directly across the main foyer was a two-story wall of floor-to-ceiling windows looking right into the heart of the canyon as it dropped about 6,000 feet to the floor below. I could see the South Rim 10 miles away (4 1/2 hours and 215 miles by car, or two days and 23 miles by foot) and, beyond that, the hazy blue silhouettes of the San Francisco Peaks.

Clinton Hart Merriam, who conducted biological studies of the Grand Canyon in the 1890s, said that from the highest peak in the San Francisco mountains (just under 13,000 feet) to the floor of the canyon at 2,000 feet were as many life zones (now called "biotic communities") as could be found from southern Mexico to northern Canada.

It was a staggering view. The sun was setting and the rock, whose pastel colors can, by day, give the canyon quite an ethereal appeal, was burning with intensity--deep reds, grays, oranges, browns and the black of shadow.

The first Westerners to stand where I stood at that moment were a small group of Spaniards led by Fathers Escalante and Dominquez in 1776 (the Spaniards had made it to the South Rim in 1540). Except for the road and lodge, little has changed since then.

The earliest evidence of human habitation of the North Rim dates to 8500 B.C. Archaeological digs have uncovered more extensive remains of the people who lived here later, about 4,000 years ago. Their split-twig figurines of deer, elk and a now extinct bighorn sheep, thought to have been used in hunting rituals, have been found in caves halfway down the canyon wall and can be seen today in the Tusayan Museum on the South Rim.

The next inhabitants, the "ancestral Puebloans" or Anasazi, cultivated crops, made ceramics, wove baskets and lived in pit houses here from A.D. 300 to 500. The remains of a pit house can be seen beside the Transept Trail, a 1 1/2-mile footpath between the main lodge and a National Park Service campground.

The Pueblo people came next. Their large excavated pueblo on the North Rim at Walhalla Overlook is a 20-mile drive from the lodge down one of the roads that snake through the forests here, offering access to walking trails and to ever more views of the canyon.

When we first visited the North Rim in 1995, we stayed in the Frontier and Pioneer cabins west of the main lodge. They are fairly classic cabins with two bedrooms joined by a common bathroom. Very simple, but very comfortable--although the lack of porches is a major drawback.

The more numerous Western Cabins are grander. The rooms are bigger, with two double beds, a table and chairs and a writing desk, all very appealingly constructed of rattan with earth-tone materials.

And then there are the esteemed Rim Cabins, where we stayed on this trip. Our rooms were spacious and airy, sensitively decorated in earth colors, wood and rattan. And ah, those porches . . .

The day after we arrived, we drove three miles from the lodge to the Widforss Trail, a 10-mile trail that winds along the rim of the canyon out to a dramatic overlook and back. As there were no barriers between us and the depths of the canyon, no signs telling us not to climb onto the numerous rock promontories that suspended us out over these depths, and very few people around to disturb the profound and ancient peace, we were able to connect intimately with the canyon. We spent most of the day just wandering and sitting and marveling at it all.

Where the trail followed closest to the rim, we walked beside wild purple lupine and under ponderosa pines, some huge. Many of the ponderosas are blackened by fire, which periodically occurs and cleans out the undergrowth and dead timber. But the bark of the ponderosa has adapted to withstand all but the fiercest flames.

At the base of these pines, we'd often see a conical pile of ravaged pine cones and bits of chewed branch, remnants of a Kaibab squirrel's recent meal. These stylish squirrels, with their dark gray bodies, tufted ears and white tails, are found nowhere else in the world except at the North Rim and farther west on Mount Trumbull, where they were stranded 10,000 years ago when the glaciers retreated.

When the trail dipped into the ravines, the ponderosas gave way to fir, spruce and aspen. And clinging to the top slopes of the canyon were the gambrel oak, a dwarfed, gnarled and abused looking tree.

The Widforss Trail--named for Gunnar Widforss, a Swedish artist who specialized in paintings of the Grand Canyon in the 1920s--ends at an overlook, with a few primitive campsites so campers can experience both the sunrise and sunset over the canyon that is unique to this spot.

The next day, we hiked down part of the 15-mile North Kaibab Trail that follows Bright Angel Canyon (named by John Wesley Powell for the "Bright Angel" in Milton's "Paradise Lost"), down past Roaring Springs, which supplies all the water to both the north and south rims. The trail takes you to the canyon floor and Phantom Ranch, a simple overnight accommodation that usually is booked up two years in advance, and then continues up the other side of the canyon, eight miles to the South Rim.

We hiked down only an hour or so, but it was enough to experience the great increase in heat that occurs once you drop below the rim (temperatures were expected to be 107 degrees at the bottom that day, compared with a high of 80 degrees at the lodge). As the North Kaibab is the only maintained trail into the canyon from the North Rim, we shared it with a steady but not overwhelming stream of day hikers and campers and mules and mule-droppings. The intimacy here is in getting right down into the canyon, up close to the rock and stunted foliage we'd spied from above.

And then it was our final night, and Jo's actual birthday. By luck, we got a window seat in the massive dining room. With its floor-to-ceiling windows and trees for beams, we felt as if we were dining in a giant's castle. And the view outside was in direct proportion. It was as if the canyon itself were a guest at our table.

The sun was setting and, as it got lower, it drew night slowly up the canyon walls in a spectacular display of light and shadow until finally only the very top layers of rock were alight. Over dessert, they too winked out, and our trip was over.

John Muir, the great naturalist, wrote, "No matter how far you have wandered--or how many famous gorges and valleys you have seen--this one, the Grand Canyon of the Colorado, will seem as unearthly in color and grandeur and quality of architecture as if you had found it on some other star."

It did. And Jo was well-feted for her 40th.

Sarah Clayton last wrote for Travel about England's Cornwall region.

DETAILS: North Rim of the Grand Canyon

Visitor facilities on the North Rim are open from May 15 to Oct. 16, after which the area remains open for day use only through Dec. 1, or until snows close the road.

WHERE TO STAY:

* Cabins at the Grand Canyon Lodge can be reserved up to two years in advance--essential for Rim Cabins. All others can usually be booked six months in advance. Rim Cabins 306 and 309 have the best canyon views; Rim Cabins 301 and 305 are close runners-up. Cabins start at $74 and go up to $124.73 for five people. Motel units sleeping up to three are $85.10 for one or two people, $91.49 for three.

* Phantom Ranch, at the bottom of the canyon, is usually booked a year or more in advance. Reservations can be made 23 months in advance. Rates are $22.87 per night per person for dormitory-style rooms; cabins are $65.96 for two, $11.17 for each additional person.

For reservations at the Grand Canyon Lodge or Phantom Ranch, call 303-297-2757 or fax 303-297-3175.

CAMPING: North Rim Campground, operated by the National Park Service, closes Oct. 15, unless the weather allows an extension. There are 80 campsites, a store, laundromat and showers, but no RV hookups. Sites are $15 per night; call 1-800-365-2267 for reservations. There are other campgrounds outside the park; the Guide (see below) provides a list.

Permits are required for overnight hiking and back-country camping, and cost $20 plus a $4 per-person per-night user impact fee. Details: Backcountry Office, P.O. Box 129, Grand Canyon, Ariz. 86023.

RAFTING: Rafting trips require reservations well in advance. The Guide has a list of park-approved operators.

MULE RIDES: Mule rides into and around the canyon can be reserved by calling the Grand Canyon Trail Rides desk, 435-679-8665, from 7 a.m. to 5 p.m. daily. For best results, call during the January preceding your summer visit.

INFORMATION: The Guide, a free park publication available in French, German, Spanish and English, has information on mule rides, rafting trips, camping services, hiking trails and side trips. Order it from Grand Canyon National Park, P.O. Box 129, Grand Canyon, Ariz. 86023-0129, 520-638-7864.

For more information, contact:

* North Rim Visitors Center, 520-638-7864.

* Arizona Tourist Board, 1-800-842-8257.

* Kaibab National Forest, 520-635-4061 (520-643-7395 in winter).

* Grand Canyon National Park Service, Attn. Superintendent, P.O. Box 129, Grand Canyon, Ariz. 86023-0129, www.thecanyon.com/nps.

--Sarah Clayton