The Big Lava Bed is the home of an old lava flow-magma oozed out of fis-sures and cracks in the heart of the Lava Bed (as well as along the lower flanks of Mount Adams, in the southern Indian Heaven area, and of course, around Mount St. Helens). The flows began some 9000 years ago and, as Mount St. Helens showed, volcanic activity in the area is still occurring. The Big Lava Bed is a volcanic formation, but it's not the classic conical volcano. Rather, it is a 20-square-mile flow of basalt that flowed out of a source vent found in the north-central part of the bed, just south of Goose Lake.

Spindly pines cover much of the Big Lava Bed, giving it the appearance of a gentle, young forest from a distance. Get near the lava, though, and the truth comes out: There is nothing gentle about this landscape.

The PCT skirts the west side of the basalt field, and almost immediately after starting the hike, the harsh nature of the lava bed is nakedly evident. Step off the trail, and the landscape is nearly impassable. The lava is abrasive, brittle, and very unstable. Try to scramble to the top of one of the short lava knobs scattered around the area, and you'll find your leather boots not just scuffed but slashed and cut to ribbons. Better to enjoy the rugged beauty of the lava flow from the relative safety of the trail.

The trail leaves the horse camp and within the first 0.25 mile meets the lava flows. The trail then rolls with the flow, as it were, skirting the rough lava on its western flank. To the west of the trail is an open pine forest scarred with clear-cuts, but the buffer of trees along the trail block most of that logging damage from view. Besides, the lava beds will keep your eyes turned away from the other side of the trail.

The terrain in the Big Lava Bed is a jumble of rock. Huge blocks of lava, towering up like black cotton-candy tufts, dot the landscape. Many of these are pahoehoe formations-wrinkled masses of rock formed by fast-moving lava. Pahoehoe is easy to identify: just look for the rocks that remind you of shar-pei dogs, a solid mass of ropey folds and wrinkles. Between the great tufts of lava are fissures, crevices, pressure ridges, and fields of sharp, jagged black basalt.

The trail follows alongside this world of volcanic turmoil for nearly 3 miles before edging away from the lava into a calmer world of pine forests. The trail rolls gently through the forest for another 3.5 miles to the southeast flank of Big Huckleberry Mountain.

For a full day of hiking, turn around where the trail leaves the lava for a short outing over to Big Huckleberry Mountain. Take note that the mountain is aptly named-in late summer the area around the mountain is flush with marble-sized purple fruit. There is no path to the mountain's forested top, so stick to the sun-dappled clearings along the trail.