The sun is setting over Canyon de Chelly. It lights the cliffs and the tops of the trees. The wash disappears in shadow. The air at the bottom of the canyon grows suddenly cold. A grandmother calls to two children, says something to them in Navajo. Then she and the children and a dog begin to climb the steep trail, up to the mesa.

She looks to be 75 years old, a wiry woman with gray hair and a lined face. She wears a skirt, in the traditional fashion.She hikes rapidly. It is as if she's been climbing this trail all her life.

Canyon de Chelly National Monument in northeastern Arizona is at the center of the Navajo Indian Reservation. The monument takes in 130 square miles that include two canyons, Canyon de Chelly and Canyon del Muerto, and scores of Anasazi ruins.

It is managed by the tribe and the Department of the Interior. The canyons are home to about 70 Navajo families, families who have been on this land for generations. Their ancestors fought Kit Carson and lost, then survived the Long March and the starving years at Fort Sumner in eastern New Mexico before they were finally allowed to go home again. Today these families farm in the wash, raise sheep and goats on the flat desert above, and run the hotels and guide the tourists.

The monument is a geological and archaeological treasure. At the same time, it's a business operation of the Navajo Nation. Canyon de Chelly is also one of the prettiest places in the Southwest.

There are so many sights we could see, if only we had a full day. We could hike to Antelope Ruins, Mummy Cave, Spider Rock or Sliding House. We could linger. We could take a picnic lunch. But we are modern, hurried tourists.

Late yesterday, on arriving at the monument, we hiked to White House Ruins. It's the only spot in the canyon where visitors are allowed without a guide. We were alone at the ruins and fell captive to the timelessness of this place.

Afterward, we drove to the overlooks along the South Rim of Canyon de Chelly. We saw darkness overtake the cliffs. We watched the bats come out. The stars were bright by the time we turned back to town. Our inability to tear ourselves away from the canyon almost cost us our dinner. We finally found one restaurant still open at 9:05 p.m.

Now it is the next morning and we want to see something of Canyon del Muerto before we start the full day's drive toward home. We are up early and at the visitors center - two women, with one large camera bag, in search of scenery.

We are assigned an authorized Navajo guide, a woman of our own age, which fools us into thinking she will take us on a hike within our abilities. She says the quickest hike would be to the Ledge ruins. We think she calls the route Bear Trail.

"You don't mind rock climbing?" she asks and we say no, not imagining she really means rock climbing, like with ropes. This is a national monument and we are, obviously, regular tourists, as likely as not to be afraid of heights. By "rock climbing," we assume she means more rocks than sand on the trail.

Just as we are about to embark, some official rearranging takes place. We get a new guide: A 21-year-old athlete, lean and lithe, named Colleen Hunter. Her dad is a park ranger. She's lived near Chinle all her life.

We drive to the trailhead, scenically located in the midst of someone's sheep herd. At this point we ask about the bears the trail was named after. "Bare," Hunter says and spells it for us. The trail is bare rock.

And steep. We start down.

At one point we watch Hunter disappear over a ledge, placing her feet in toe-holds that have been chiseled out of the stone. She descends cautiously until all we can see is her hand grasping the top of the ledge.

This is when we finally get it. What that first guide meant by "rock climbing." It is more than we bargained for.

We will ourselves to keep moving. To pause is to freeze up. We try not to look straight down. We look out instead, over the edges, to the green valley below, to a small house and a hogan and an orchard.

Soon we make it, down one last rocky ledge to the river. We sit on a sandbar to take off our shoes. We relax. We feel chatty. We ask Hunter if some tourists actually start to cry on this hike and have to turn back.

Yeah, she says. Some do. Turn back. Not cry.

Hunter is reserved. Not prone to drama. Over the course of several hours, as we wade together through the water, she gives a succinct tour, naming trees and birds and telling about the Anasazi. She talks of her life, too.

She calls her ancestors her grandparents, not numbering the greats and great-greats. In the traditional way, she calls her cousins her brothers and sisters. As she speaks, prehistory becomes personal, immediate.

Before she became a tour guide, Hunter took no special interest in these canyons, she says. Now she comes here gladly, even on her day off. She observes. She tries different ways down. She challenges herself.

One night last year, preparing to descend by moonlight, she fell 50 feet. She was taken by helicopter to Albuquerque with internal bleeding and broken bones. For a time, she lost her nerve for the steep edges.

But the canyons drew her back. In the middle of the desert, they offer water, trees, grass, game. For centuries they've been a refuge.

Archaeologists have found more baskets here than in any other part of the Four Corners region. Hundreds of Anasazi lived and farmed here, beginning before 300 A.D. The large pueblos were built around 1000. The droughts began in 1270, which may be why the Anasazi were gone by 1300.

Canyon de Chelly may have been the last of the desert canyons to lose its water. People from Mesa Verde and Chaco Canyon felt the drought first - they may actually have immigrated to Canyon de Chelly for a few years. Some hasty cliff dwellings were built, in the late 1200s. But soon all the stone houses were abandoned. No one knows what happened to the people.

No drought this year in Canyon de Chelly, however. It wasn't until May, Hunter explains, that they were able to drive their four-wheel-drive vehicles up the wash. Tourists had to walk in. So did the residents.

Now the Jeeps are back. Various tours pass us as we walk to the ruins. Guides call out to Hunter in Navajo. She answers in English.

At Ledge ruins, Hunter describes three styles of rock construction practiced at different times by the Anasazi. She draws diagrams in the sand. Some of what she knows, she learned in college. Some she learned from older relatives.

Park Service publications translate the Navajo word "Anasazi" as "ancient ones." Hunter translates it as "ancient enemies." Her people had a lot of enemies, she explains, beginning with the time they moved south from Canada, finally settling in these canyons in the 1700s.

The Hopis already living in the area became the Navajo's enemies - along with the Utes, the Spanish, the Pueblos and the U.S. Army. Hunter thinks the word enemies means her people had direct contact with the Anasazi.

After the ruins, Hunter takes us to her favorite rest spot. We sit in the shade of an overhang and look at a pictograph from the mid-1800s. A Navajo sheepherder sat here to paint his memory of a battle.

In fact, the early history of the Navajos in this canyon is a history of battle - raids and counterraids. Disputes erupted with the Spanish and Utes over livestock and slaves, and later with the U.S. Army.

On the wall, Hunter points out depictions of soldiers, Utes fighting alongside them on horseback with rifles. The Navajo men are on foot, only a few have guns. The Navajo women are on a ledge, throwing rocks down on the enemies. The Navajo children and livestock are safe, temporarily, on the mesa above.

There are only two canyons in this monument, two medium canyons, nothing as grand as what the Colorado River has carved a few miles down the road.

Yet the Canyons de Chelly and del Muerto are grand on their own scale. Grand in history and in scenery. After spending the morning hiking the Bare Trail, we cease to wish we had one more afternoon and start to wish we had two or three more days to spend here. Climbing out, we forget to be scared.

We drive back to the visitors center, stopping at the mouth of the canyon to watch a horse tour trotting forth. Merrily, they go splashing up the middle of the wash.

Creamy cliffs, blue sky, frisky horses. The romance of the scene holds our attention for a time. Then we notice the Oldsmobile.

An ancient, rusty passenger car is driving, slowly, steadily across the wash. We feel compelled to see what happens next. It passes midstream without floating off. We tourists assume the danger is past.

Hunter keeps watching. Sure enough the car gets stuck within a few yards of the bank. She says she knew it would happen. Quicksand is worse at the edge.

Four slim, black-haired figures get out of the car and stand motionless as the rear wheels and bumper keep sinking, disappearing under the sand. Then they walk to dry ground. How will they ever get that car out? With a jack, says Hunter. Why won't the jack sink? They'll put a board under it, she says.

Her voice is unemotional. Same thing happened to her last week, Hunter says. In a Jeep, she adds. It's been a rainy spring. She shrugs.

This is what it means to live on the mesa and work in the canyon. Her grandparents never promised the way would be easy. They only said she would walk in beauty.

*****

ADDITIONAL INFORMATION

If you go to Canyon de Chelly

The name Canyon de Chelly (dah-SHAY) comes from the Navajo word "Tsegi" (tsay-yhi) which means "rock canyon." Thus, when we say Canyon de Chelly, we are actually saying, "Canyon Rock Canyon." If, in spite of the redundancy, you want to visit, here's how:

Getting there: Highway 191 leads from Southeastern Utah to Chinle, Ariz. From Chinle, take Route 7 east for 3 miles, to the Canyon de Chelly visitors center.

There is no entrance fee for the monument. Beware of quicksand, cliffs, loose rocks and flash floods.

The visitors center is run by the National Park Service and offers maps, a museum, a film, a short nature trail. Rangers can help arrange for hiking guides or Jeep tours. The visitors center is open daily; from 8 a.m. to 5 p.m., October to April; until 6 p.m. May to September.

Where to stay: Rooms are available inside the monument at Thunderbird Lodge, Box 548, Chinle, AZ 86503, 520-674-5841. A portion of the Lodge dates back to 1896, when it was a trading post.

There is also a Holiday Inn and a Best Western in Chinle. Also within driving distance are the motels of Window Rock, Ariz.; Monument Valley, Utah; and Gallup, N.M.

Camp sites are available within the monument - first-come, first-served - at the privately owned Cottonwood and Spider Rock campgrounds. Reservations accepted for groups over 15. Cottonwood has 96 RV hook-ups. Back-country camping is also allowed, with an authorized Navajo guide.

What to do: Drive the roads along the South and North Rims. Stop at the viewpoints.

Hike - on your own to White House ruins, with a guide to any of the other sites. Guides are available at the visitors center. (Be there by 9 a.m. if you are worried about grabbing a guide before they all go out.) A hiking guide may take up to 15 people into the canyon. They charge $10 an hour.

Half-day or full-day four-wheel drive tours up the wash are available unless the water is high. Costs vary from $34 for a half-day large-group tour, to $100 for a half-day Jeep tour. For Thunderbird Lodge Canyon Tours, call 520-674-5841; Tsegi Guide Association is at 520-674-5500; and De Chelly Tours is at 520-674-3772. You may take your own four-wheel up the wash, provided you go through the visitors center for a Park Service permit and an authorized Navajo guide.

To tour on horseback: Justin's Horse Rentals at 520-674-5678; Twin Trail Tours at 520-674-8425; and Totsonii Ranch at 520-755-6209.

Food: There is a cafeteria at the Thunderbird Lodge; no other food available within the monument. There are drive-ins and several other restaurants in Chinle (probably the most upscale being the one at the Holiday Inn, just west of the monument on Route 7.) Also a grocery store, with deli, in Chinle.

Carry your own water into the monument. You can fill bottles at the visitors center. Liquor is not allowed on the Navajo Reservation.

- Susan Whitney