Taking the high road to devastation, rebirth : Spur off I-5 now goes within 8 miles of Mt. St. Helens. Tourists can get a closer view of crater.

After 13 years, the volcano hides no more.

A new spur highway off Interstate 5 between Portland, Ore., and Seattle now takes motorists into the 1980 blast zone, to within eight miles of the dozing Mt. St. Helens for a gunsight view into the steaming crater.

Now, it is possible to witness first hand the eerie moonscape of devastation that resulted from the explosion on May 18, 1980--the most catastrophic volcanic eruption of modern times in the continental United States--and to behold the exuberant rebound of nature as it regains footholds in the ash and mud, amid the charred remnants of countless millions of trees.

Until this spring, Mt. St. Helens had been visible only from the air, from distant highways or after a difficult drive over Forest Service roads. The visitor center off the I-5 highway was little more than a tease compared to the wonders that lay hidden over the ridgeline.

But plowing a pathway to this restless mountain has not been easy.

At a cost of $130 million, the state of Washington has finally rebuilt 30 miles of state Highway 504 destroyed by the eruption. The new highway heads east from Interstate 5 at Castle Rock, about an hour’s drive north of Portland. It has been relocated higher on the slopes of hills in an attempt to shield it from future ash flows down the valley of the Toutle River.

At the end of the new road is the just-dedicated and architecturally breathtaking Coldwater Ridge visitor and interpretive center. Operated by the Forest Service, the $11.5-million facility is the starting point for a network of gentle paths and trails through the charred landscape.

Here, among remnants of twisted trees, a whole new cycle of life is taking hold. Purple penstemon and other wildflowers paint the hillsides; seedling conifers rise several feet high; cascades of water lick down the steep slopes.

During the eruption, the material that once made up the top--and the guts--of Mt. St. Helens poured into the river valley below. In colors of brown and gray and rust, the sediments now form a vast plain, in some places 600 feet thick and two miles wide. Atop the plain, the muddy, khaki-colored Toutle carves the next great canyon of the region.

Beginning with parachute spiders, carried on the wind in the year following the great explosion, plants and animals have recolonized the slopes of Mt. St. Helens and the surrounding region. Of the known flora species, 72 of 95 have returned to the mountain. From the elk to insects, all known animals of the region have returned, although in often depressed numbers.

But what of the volcano itself?

Steam still vents from the 1,000-foot-tall hot lava dome that rose inside the crater following the last eruption, and small earthquakes continue to remind the mountain’s neighbors of goings on inside. But activity is at its lowest since 1980. Non-scientists, compressing time by their own hurry-up clocks, tend to deduce that the mountain is going back to sleep.

“Yes, it could be an indication we are entering a long period of inactivity on the mountain,” says Steve Brantley, spokesman for the U.S. Geological Survey Cascades Volcano Observatory.

“It could be also that this is just a quiet interlude before renewed eruptive activity--perhaps in a few years or in a few decades.”

The geological service continues to rate Mt. St. Helens as the most serious threat to human life and property of any of the Cascade volcanoes.

Based on its history, Mt. St. Helens seems “fairly reliable” in giving plenty of notice before exploding back to life. The primary 1980 eruption was preceded by a significant buildup of earthquakes as molten magma squeezed its way up from under the crust of the planet.

However, the mountain does not necessarily give warning of the smaller explosions that are caused by water seeping into hot cracks in lava and being flashed into steam, or that occur when trapped gasses burst free of cooling rock. A series of those types of surprise explosions occurred in the winter of 1990-91 and resulted in ash plumes, hot rock avalanches and small mud flows that came weeping down the north flank of the mountain.

In the future--Mt. St. Helens willing--engineers plan on pushing the highway still closer to the mountain. In 1996, an observatory is to be opened on a high point five miles from the crater on Johnston Ridge, named for the late David Johnston, a geochemist and one of at least 57 people who dared stray too close on that worst of days 13 years ago.

Times researcher Doug Conner contributed to this story.