Hike of the Month

Trek a Frozen Moment in Geologic Time

Hiking a cave? The first thing is lights: A lantern to illuminate your footsteps across the rock-littered cave floor is ideal although a couple of flashlights could suffice.

We borrowed our lights from a Forest Service volunteer who lives near the Lava River Cave outside Flagstaff.

The second thing is warm clothes: I'm wearing a sweater, nylon pants, jacket, and woolen cap. Standing outside in full sun, temperature around 70° F, I feel a bit absurd all bundled up. But a cold draft rises from the cave entrance, and I know that, day and night, year-round temperatures inside range from near freezing to 45°. After a few minutes, the cold begins to seep into your marrow.

Our guide is Forest Service recreation specialist Steve Jenner, who knows every nook and (BELOW) At its highest point, the ceiling in the Lava River Cave near Flagstaff, soars to 30 feet. But in the middle and toward the end, it drops considerably, as hiker Peter Ensenberger discovers.

(OPPOSITE PAGE) In one of the largest rooms of the cave, it splits into two tunnels which rejoin a little farther along.

In cranny of the Lava River Cave. During the summer of 1991, he headed a volunteer crew that sandblasted graffiti from its walls. "Some of it was pretty accomplished art," says Jenner. "I kind of hated to take it off, but we want the cave to be as pristine as possible."

The approximately 700,000year-old cave is actually a lava tube, formed when lava from a nearby volcano flowed molten, creating a tunnel. At 3,820 feet, the Lava River Cave is the longest lava tube in Arizona.

For hikers the toughest part is the descent into the cave. The entrance is a large sinkhole where the roof collapsed, strewing tons of boulders, which are sometimes icy in this, the coldest part of the cave.

Forewarned, I wear my best boulder-hopping hiking shoes, yet feel uncertain and unsteady. A bigger problem than the footing is the light. My flashlight is ineffective in the hazy light at the cave's entrance, and I am disoriented and groping until we descend into absolute blackness where artificial lights can really work.

Once we get past the boulder dump and into the lava tube itself, we're able to concentrate less on footholds and concentrate less on footholds and more on our surroundings.

Two things strike us immediately: the darkness and the quiet. It is so black inside the cave that if you turn off your lights, you cannot see your hand even if it's touching your nose. And the lava walls muffle sound so thoroughly, you hardly know there are other people around.

Many popular caves are limestone with fantastic stalactites and stalagmites. Lava caves are different. What you see instead are unique lava formations.

Two of these are "pahoehoe," pronounced pa-hoy-hoy, and lavasicles.

Pahoehoe refers to ripples or waves that form when lava quickly solidifies, so that the floor of the cave is a river of lava.

Lavasicles resemble small stalagmites or stalactites. After the walls and ceiling hardened, a blast of hot gas swooshed through the tube, remelting the lava surface and creating drips. These drips then cooled rapidly and hardened into lavasicles.

Although the Lava River Cave is only about three-fourths of a mile long, our hike to the end and back takes two hours.

About one-third of the way in, the cave forms two passage ways that rejoin after a short distance. At the halfway point, a low ceiling forces us to duck walk for about 10 yards. Aside from that, it's a pretty straight shot. But even with lights, hiking a pitch-black cavern is slow going.

Chilled to the bone when we return to the cave entrance, we shed our outer garments and, like fists unclenching, spread our limbs to the sun.

To reach the Lava River Cave from Flagstaff, take U.S. Route 180 north to Milepost 230; turn left onto Forest Service Road 245 and travel west for three miles to FR 171. Continue south on 171 and then 171B for one mile to the cave. The Forest Service recommends each person have three sources of light and wear sturdy shoes, warm clothes, and a hard hat. Also, leave notice with friends of your planned trip and return time. For more information, contact the Peaks Ranger District, Coconino National Forest, 5075 N. Highway 89, Flagstaff, AZ 86004; (520) 526-0866.