This story appears in the May 2010 issue of National Geographic magazine.
Beer cans once lay at the bottom of Spirit Lake. Mark Smith remembers them perfectly: 20-year-old Olympia flattops, their shiny gold lettering somehow preserved by the clear, cold water. He remembers ten-inch rainbow trout: planters for the tourists. He remembers a sunken rowboat from the YMCA camp, its bow resting on a submerged stump. A teenager when he began scuba diving in the shadow of Mount St. Helens, he remembers the lake as it was before the May 1980 eruption, before the top 1,300 feet of the volcano—more than three billion cubic yards of mud, ash, and melting snow—avalanched into it. Before the lake became twice as big but half as deep. Before virtually all evidence of life, animal and human—the cabins and roads and camps and cans—were obliterated. Before the lake became a stinky soup, devoid of oxygen and covered with a floating mat of tree trunks ripped from the landscape. What Smith remembers best is what he called the "petrified" forest: a ghostly stand of sunken, branchless firs, buried upright dozens of yards below the surface. The underwater forest was a mystery to him until the mountain exploded. Then it made perfect sense. The trees were evidence of a past eruption—a sign Spirit Lake has always been in the line of fire.
Three decades later, Spirit Lake holds a new mystery: How did fish, now twice the length of those pre-eruption rainbows, reappear? Everyone has a theory. Smith, who runs Eco Park Resort at the edge of the volcanic monument, thinks the trout slid down from smaller, higher St. Helens Lake during a flood year. But that lake has only mackinaw—and the Spirit Lake fish are rainbows. Biologist Bob Lucas of the Washington Department of Fish and Wildlife believes someone illegally planted them. In the late 1990s, an anonymous call to his home seemed to confirm it: "I'm the one who stocked the fish." Preliminary genetic testing by Forest Service ecologist Charlie Crisafulli also suggests the trout did not descend from the pre-eruption population, but he's given up on figuring out their origin. "There are as many stories as there are fish tales," he says, "and all of them start, 'I know somebody who put those fish in there.' " To him the important question is not how they arrived but how they grew so big. On the 30th anniversary of the May 18 eruption, one of the only things certain about the trout in Spirit Lake is that they've given everyone—environmentalists, scientists, fishermen, congressmen, rangers, and business owners—something else to argue about.
Mark Smith grew up at the lake, where his family ran the lodge one down from the one owned by Harry Truman, the famously cantankerous 83-year-old who shared a name with a President and was among the eruption's 57 victims. As a boy, Smith fished there. Today he'd have to break the law to do so. He's not saying he does, but if ever I want to join him, he is, ahem, very familiar with where a poacher could sneak in. "We were lost!" he yells, practicing his alibi. "We just saw this and started fishing!" The 2,700-acre lake now sits at the center of a restricted research area taking up roughly a quarter of the 110,000-acre Mount St. Helens National Volcanic Monument, which Congress set aside in 1982 "to protect the geologic, ecologic, and cultural resources … in as natural a state as possible, allowing primarily natural geologic forces and ecological succession to continue unimpeded." Mostly closed to the public, this part of the blast zone has become one of our planet's grandest experiments.
The volcano came back to life from 2004 to 2008, shooting off plumes of steam and ash up to 30,000 feet into the sky, growing a new lava dome in its crater, and captivating sightseers and geologists. But many of the area's greatest insights have come in the field of ecology.
As a natural lab to study the rebirth of ecosystems, the blast zone has no equal. "It's the most thoroughly studied large-forest disturbance in the world," says Crisafulli, examined from nearly every angle, at nearly every scale, from molecules to ecosystems, bacteria to mammals, steaming geothermal vents to waterlogged meadows. Almost daily, callers inquire about the lessons of St. Helens. One woman is interested in salamanders, another in toads. Officials in Alaska and Chile want to know what to expect after eruptions of their own.
A key lesson is the importance of "biological legacies"—fallen trees, buried roots, seeds, gophers, amphibians—that survived the blast, thanks to snow cover, topography, or luck. Ecologists had assumed rebirth would happen from the outside in, as species from border areas encroached on the blast zone. But recovery has also come from within. Starting with a single plant Crisafulli discovered in 1981 on the barren, 3,750-acre expanse known as the Pumice Plain, purple prairie lupines became the first color in a world of sterile gray. In life they were nutrient factories, food for insects, habitat for mice and voles; in death they, and the organisms they attracted, enriched the ash, allowing other species to colonize. Gradually the blast zone began to bloom.
Take a broad view, and you see that humans are also part of the St. Helens experiment. What captivated the country 30 years ago was not just the size of the blast but that it happened to us, to people we understood and a landscape we loved. Now, as nature springs back and memories fade—and budgets and visitor numbers fade as well—humans are becoming restless. Some say the monument should be wrenched from the Forest Service and made a national park. Others hear tales of two-foot trout and wonder why Spirit Lake is still off-limits. Last spring a bill to open it to limited fishing passed 95 to 1 in the Washington State House before stalling in the senate. Some locals grumble that 30 years of research is enough—that it is time to open the restricted zone. None of this should surprise us. Even on a human scale, St. Helens is an ecosystem trying to find equilibrium.
What I remember from my swim in Spirit Lake is not a sunken forest but an underwater jungle. Last August I drove behind Crisafulli on a sinuous two-lane road along Windy Ridge, through a damaged gate secured by a makeshift chain—"You'd think there'd be enough money to buy a new damn gate," Crisafulli said—and down a scary, slopeside jeep trail into the restricted area. At the edge of the Pumice Plain we began the two-and-a-half-mile walk that the lean 52-year-old has taken thousands of times. His ponytail swung with each step. He talked ecology almost nonstop, his New York accent still discernible after 30 years in the blast zone. Behind us was the volcano, snowless and gray, its northern wall collapsed, its crater exposed. In front was the lake, its surface calm and two-fifths covered by the "log raft," a shifting mass of thousands of floating logs. Along the trail were fir saplings, lupines, and Indian paintbrush, 15-foot-tall thickets of willow and alder, and, near a stream, hordes of toads and tree frogs. At the lake's edge, we got into warm fleece overalls that Crisafulli called bunny suits, into dry suits and masks and snorkels, and into a Zodiac raft, which motored into Duck Bay. And then into the frigid water.
The first surprise was the colors: brilliant yellows and greens, electric in the sunlight, a world apart from the drab Pumice Plain. They belonged to aquatic plants, thick, vinelike macrophytes stretching ten feet from lake bed to surface. Mossy clumps were suspended above the silt. Everywhere I turned were fish, hook-jawed and fat, all of them 20 or more inches. I swam after them. They didn't spook. The sunken jungle, I noticed, was only in the shallows. In deeper water it was gone—and so were the fish.
Before the eruption Spirit Lake was, like many subalpine lakes, unproductive and nutrient-poor, with clear water and few shallow spots. When the volcano top slid into it at 150 miles an hour, it became choked with what Crisafulli terms "pyrolyzed forest constituents"—organic material burned in the blast. The water was warmed to body temperature, filled with dissolved carbon, manganese, iron, and lead. Visibility went from 30 feet to six inches. Bacteria flourished. The first scientists to take water samples came down with unexplained ailments. There was a rapid succession of microbes: aerobes, which quickly used up all the oxygen; anaerobes, which require none; then nitrogen-consuming bacteria; and then forms that fed on methane and heavy metals. For 18 months Spirit Lake was ruled by chemistry, home to "hundreds of millions of bacteria per milliliter," Crisafulli says. Finally, the microbes had consumed so much that they began to die off, and streams and snowmelt came in, and the water cleared.
Once light penetrated Spirit Lake, algae and other phytoplankton colonized, followed by zooplankton, which fed on the phytoplankton, followed by aquatic insects and amphibians. By the early 1990s, macrophytes grew in shallow shoals—ideal trout habitat that didn't exist before the eruption. Gorging on tiny midges and freshwater snails, the rainbows were reaching a record four or five pounds in two or three years. The post-eruption lake followed a pattern Crisafulli would see many times in the blast zone. New organisms colonize the virgin environment with dramatic success, only to burn themselves out or be checked by predators, parasites, or competitors. This was the second revelation of St. Helens: When there's a blank slate, ecological succession is a cycle of boom and bust.
Spirit Lake's richness is spilling over. When a tadpole dies as a frog on the Pumice Plain, when an insect hatched in the lake is deposited in the ash, their nutrients are transferred to land. Slowly this process undoes what the eruption wrought. "Before the eruption, the terrestrial environment was superproductive," Crisafulli says, with "lots of nutrients and carbon tied up in the old-growth forest. In comparison, the lake was impoverished. After the eruption they flip-flopped." Now the landscape is going back from gray to green, and the lake is becoming more like its former self.
At 20 inches and two and a half pounds, the rainbows I saw were as large as any I've caught in a lifetime of fishing the Pacific Northwest—but the fish, too, were becoming more like their former selves. Nine years after Crisafulli began tagging them, either because Spirit Lake is becoming less productive or because too many trout now vie for the same amount of food, or both, their average weight has been cut in half.
Some fly fishers see the ongoing changes in Spirit Lake as a problem—of overpopulation—and offer themselves as the solution. "There's a world-class fishery going untapped, and it's the right of the citizens to fish it," Denny Way tells me. The president of the Clark-Skamania Flyfishers club, he's proposed opening up Spirit Lake before the trout shrink: ten catch-and-release fly fishers, along with a trained host, one day a week. The scientists, meanwhile, note that a dozen neighboring lakes are open to fishing but are undervisited and that at Spirit the danger is not the numbers but the precedent: ten fishermen or a hundred, the door would be open. Nominally about fish, the argument goes deeper: What should the monument be for?
The question is everywhere. If the two decades following the eruption were the monument's boom—five visitor centers, hundreds of miles of roads, millions of sightseers—today has the appearance of a bust. The largest center, Coldwater Ridge, where exhibits focused on biological recovery, closed in 2007 as budgets shrank. The west side has only two full-time interpretive rangers; the south and east, only one. The monument's life-support system is volunteers from the nonprofit Mount St. Helens Institute, seasonal workers, and interns. Seventy percent of its roughly $1.8-million recreation budget comes from user fees. The rest is tied to that of Gifford Pinchot National Forest, and funds increasingly go to firefighting. While statistics are scarce—another victim of the budget crunch—monument staff and business owners like Mark Smith agree that visitation has fallen far from the heyday of the 1980s and '90s. A quarter of those who now come are foreigners, who camp out or stay in nearby lodges. Americans tend to make day-trips, driving up Spirit Lake Memorial Highway and past the shuttered Coldwater center to an overlook, then heading back to Interstate 5.
Some hope for a Mount St. Helens National Park, with congressional funding, lodging, and more money for more science. Funds are starting to flow, with more than $6 million in federal stimulus last year, plus a $163,000 grant to the Mount St. Helens Institute for an exhibit at the end of the Spirit Lake Memorial Highway. The 30th anniversary means renewed interest. "In my talks at St. Helens I tried to get people to realize that the volcano is not static," says the National Parks Conservation Association's Sean Smith, a former St. Helens ranger now pushing for park status. "I'd hold up an Etch A Sketch and say the monument's like this drawing. The forces of nature control one knob. The public has the other."
"In the larger story of St. Helens, park versus monument is a blip in history," says monument staff scientist Peter Frenzen, who started alongside Crisafulli in the weeks after the eruption. "Access to Spirit Lake is a blip in history." Those who've walked the blast zone for three decades see the beginning of a more profound process. Breakthroughs are fewer—one plant pushing through the ash is no longer a miracle—but the pace of change is accelerating, the scale broadening. Instead of eureka moments, there is something approximating wisdom.
"Right now, the Pumice Plain is like a runaway horse," Crisafulli says. "Individual plots can't address the evolution." He plans to survey by satellite and airplane—tools that can see the big picture as the pixels fill in. "We're moving to broad-scale biogeography," he says. "It's the next frontier."
Another sunny day last summer, I again hiked across the Pumice Plain, this time to join three young scientists Crisafulli had recruited to survey Spirit Lake. The goal was to create the first ecosystem-scale map of the aquatic environment—patches of plant life, submerged mounds that had slid from the top of the volcano, fish in the water column. An echo sounder clamped to our boat's starboard side, our motor idling, our wary eyes on the log raft—it could cut us off on the wrong side of the lake if the wind blew—we crept forward. St. Helens, what was left of it, filled the horizon. On a digital display, the scientists pointed out strange squiggles—either trout or sunken logs, suspended vertically. We wouldn't know which until the data went to the lab. So they took me to a shallower spot, just south of what used to be Harmony Falls, where they knew what they were looking at. When I peered into the clear water of Spirit Lake, I also knew. Three decades after the eruption, with the mountain calm and the lake alive, I saw what Mark Smith had seen: a petrified forest.