HIKING

HIKE OF THE MONTH BONITO LAVA FIELDS NEAR FLAGSTAFF

For nearly 180 miles, I've been driving steadily south toward Flagstaff, returning to Phoenix from an assignment that has taken me deep into the rugged Arizona Strip north of the Grand Canyon. It's time to stretch my legs. But where? Visible ahead, on either side of U.S. Route 89, are two extinct volcanoes, and their presence provides my answer. Off to the right are the majestic San Francisco Peaks with 12,643-foot Humphreys Peak, an "old" volcano that erupted 1.8 million years ago. Now, in late May, the peaks remain cloaked in deep snow. Beautiful.

To the left of the highway is Sunset Crater, a young cinder cone, 8,000 feet above sea level, a volcano that erupted as recently as A.D. 1064-1065. While the larger San Francisco Peaks to the west are covered with forests of ponderosa pine and quaking aspen, Sunset Crater is essentially devoid of plant growth, its 1,000-foot-high conical form composed of nearly a half-billion tons of black cinders with a rim of reddish cinders. Dramatic. Moon-like. So much so that Apollo 17 astronauts were trained at the site.

As I view Sunset Crater from a distance, I'm swept back in time by a wave of nostalgia. In 1942, when I was 12, my family moved to Flagstaff, and I was given almost limitless opportunities to fish, hunt, and hike in the Coconino National Forest. Among a multitude of other outdoor experiences, I once climbed Sunset Crater. So, that's it: I'll stretch my legs with a repeat ascent.

But a ranger at Sunset Crater Volcano National Monument tells me, "No." A continuing increase in climbers was threatening the delicate environment of the cone, so the trek to the top no longer is permitted. I'm disappointed. "No need to be," he says. "We have the self-guided hike through the Bonito lava fields, and, for a gorgeous view, you can climb to the rim of Lennox Crater." He's a good salesman. I'm off!

SUNSET CRATER VOLCANO NATIONAL MONUMENT

The ranger supplies me with a comprehensive trail guide with symbols that match the various stop-off points along the route. This is a distinctly nonstrenuous hike of only one mile, but it captures my attention totally, taking me through a convoluted land of black lava and cinders, a place of strange "otherworldly" formations.

For example, "squeeze-ups." To me they look like giant shark's teeth, more than 10-feet tall, sticking out of cracks in fields of hardened lava. I walk past what once were fumaroles and spatter cones. My printed trail guide explains. These were simply volcanic "burps," minivolcanoes scattered across the seemingly endless acres of hardened lava. Lava bubbles, too. These are even smaller burps that never truly erupted.

There's also a 225-foot underground lava tube, a twisting cave, its walls mantled in ice most of the year. I explored the ice cave when I was 12, but now it is off-limits, too, with the interior unstable and deteriorating.

Strangely, perhaps, the lava here has a Hawaiian name: ahah, which hardens into sharp jagged forms. Good reason to stay on the hiking path. An inadvertent fall could produce some nasty cuts and scrapes.

With more than a dozen tour stops along the trail, the hike through the lava fields can take the better part of an hour. Once completed it's time for a little exercise to be provided by the half-mile trek to the top of Lennox Crater.

Less than half the vertical height of Sunset, Lennox Crater has stands of ponderosa pine on its slopes. For those visiting from lower altitudes, the rarefied air well above 7,000 feet can produce a nicely elevated pulse rate, deep breathing, and the feeling once you reach the top that you've had a fairly good workout.

From the rim of Lennox, the panoramic view is extraordinary, and the hike back, all downhill, is pleasant. If, afterward, you are in the mood for more walking, you can drive about 18 miles along the Loop Road to Wupatki National Monument. There you can explore ruins of a prehistoric Indian culture that built extensive multistoried pueblos with a rather precisely engineered outdoor amphitheater, a large ball court, and other associated structures. There are four different and widely dispersed archeological sites at Wupatki, so you can walk until your legs say, "Stop!"

WHEN YOU GO

Getting there: The entrance to Sunset Crater Volcano National Monument is located about 14 miles north of downtown Flagstaff on U.S. Route 89. Once inside the park, the staff at the visitors center will provide you with a map of both Sunset Crater and Wupatki national monuments, plus a printed tour guide for the lava fields. Wupatki can be accessed by the Loop Road directly from Sunset Crater. For more information, telephone (602) 527-7042.

Nearby accommodations: Just outside the main entrance to the monument is Bonito Campground with parking spaces for RVs or automobiles. No advance reservations. Overnight, $7.00 per day, $3.50 for Golden Age and Golden Access Passports.

Admission fee: There is an admission fee of $3 per carload, valid for one week, that covers both Sunset Crater and Wupatki national monuments. U.S. citizens who are 62 years of age and older or who have permanent disabilities may visit at no charge, along with all other passengers in their vehicles.

Hiking Guide: For a guide to hiking in Arizona, we recommend Outdoors in Arizona: A Guide to Hiking and Backpacking, a collection of 48 great hikes through desert, mountain, and canyon environments, including easy-toget-to trails in urban areas. To order, telephone toll-free 1 (800) 543-5432; in the Phoenix area, call 258-1000.