The first scientific expedition to the glacier was in 1914, when it was proposed that the Rocky Mountain locust was the creature embedded in layers within the ice. Specimens were collected on four subsequent expeditions between 1919 and 1952, but none were preserved. For a while there was even a flourishing tourism industry, with jeep tours taking people to the glacier from Cooke City, Montana (sardonically nicknamed “Cooked City” when the 1988 Yellowstone fires swept to the edge of the town).
Perhaps the greatest source of speculation concerned the age of the locusts. Since the 1930s respectable publications had reported that the swarms had been entombed “since prehistoric times,” and a credible entomologist, Arthur G. Ruggles, maintained that the insects were hundreds of thousands of years old. In 1953, Ashley Gurney conducted the first and only scientific study of grasshoppers preserved in glacial ice prior to our work. He asserted that the Rocky Mountain locust comprised the layered deposits, but he noted that a few years earlier a colleague had collected live specimens of another migrant species, Melanoplus rugglesi. Ironically, this species had been named for Arthur Ruggles, the man whose wildly speculative estimate of the age of the locusts in the glacier was about to be refuted. Gurney used radiocarbon dating to estimate the age of specimens from the glacier. Unfortunately, the analytical methods of the time were quite imprecise, and the resulting age of the insects was reported as 45 ±650 years. This was a very difficult value to interpret and may have arisen from relatively old specimens, although far less than 100,000 years, having been contaminated with recently deposited material.
When we arrived in 1987, a weathered sign—painted on a dilapidated cabin, announcing “Jeep Tours to Grasshopper Glacier”—was Cooke City’s last remnant of the glacier’s heyday as a tourist attraction. By the time of our expedition, a wilderness border had been declared between Star Lake and Goose Lake, four miles short of the glacier. We were, however, heavily equipped with camping, climbing, and traveling gear—along with a U.S. Forest Service map that included a tentative, broken line that purportedly traced the trail from just outside Cooke City into Grasshopper Glacier. I’d long since learned that such markings on Forest Service maps represent an odd combination of rumor, folk wisdom, and seat-of-the-pants cartography. The former jeep route had deteriorated to a meandering ghost trail.
Fortunately, my team had a sense of adventure. Dick Nunamaker, a research scientist with the USDA laboratory on campus, lived in a tiny log cabin on the windswept plains outside Laramie, so he was well adapted to adversity. Larry DeBrey, my research associate, had been a construction worker, a logger, and a firefighter, so the expedition was well within his comfort zone. Tim Christianson, my doctoral student, had been working on a demanding field project studying insect communities in a sagebrush shrubland at 9,000 feet, so he was conditioned for the trek.
Within the first five miles, we had lost the trail twice and changed a flat tire. The road was so bad that the other three fellows decided to walk in front of the four-wheel-drive truck that was hauling our gear. Their logic was that they could hike faster than I could drive, so they could scout ahead for passable routes. And walking involved far less physical abuse than banging around in the cab or bed of the truck—not unlike the logic used by pioneers who chose to walk alongside the prairie schooners. At times, my crew took to rolling small boulders from the badly eroded track in an attempt to preserve the oil pan and avoid using our last spare tire. In the course of seven hours, we traversed the fourteen miles to Star Lake. This serene site was surrounded by craggy outcrops and a few courageous pines—a perfect location for a camp. Angry gray clouds soon rolled over the distant peaks, and a fierce wind buffeted our tents all night.
The next morning dawned crystal clear, with a heavy dusting of snow on the higher peaks—not an unusual condition for August in the high country. With light packs, we headed out from camp and around Goose Lake, which stretches from the wilderness border to the pass that would take us up to Grasshopper Glacier. The thin patches of stunted trees above camp quickly gave way to patches of alpine meadows and by the time we reached the pass, the only signs of life were palettes of orange, green, and gray lichen splattered on granite boulders, some scattered tufts of grass sprouting from the windblown soil between the rocks, and a few mountain goats across the way. As we reached the top of the pass and crested the ridgeline, the glacier came into view. The great crescent of ice rested in a classic cirque, an immense bowl of rock at the head of a boulder-strewn valley. The saddle was flanked by Sawtooth Mountain’s Iceberg Peak and Mount Wilse’s Glacier Peak. Winds funneled up the granitic gorge and across the ice—a perfect trap for any airborne insects attempting to cross the Beartooth range.
Our thrill at having successfully reached the glacier was quickly dispelled, as we realized that the frosty spectacle was courtesy of the previous night’s storm. Two inches of fresh snow covered the ice—and buried any chance of seeing grasshoppers at or near the surface. A couple hours of scraping and searching convinced us of the futility of attempting to locate specimens under these conditions. We were seeking needles in an immense, frigid haystack. But mountain weather is notoriously fickle, and what the clouds bring the sun soon takes away. Although it was evident that the day would yield nothing more than a couple of reddish tibia collected from a patch of exposed ice beneath a boulder, we also realized that the snow was rapidly melting.
Over the next three days, the glacier was stripped of its snowy mantle, and the pitted gray ice was revealed. The warm days sent torrents of water down the face of the glacier, making the work wet and treacherous. The constant hazard was falling, as the resulting slide could quickly deposit a careless climber over the low shelf at the toe of the glacier. The short drop would end with a plunge into the sapphire blue meltwater lake that fed West Rosebud Creek far down the valley. With ice axes and crampons, such a spectacular descent was unlikely, but slips and stumbles were not uncommon. Such mishaps yielded painful reminders of the virtues of keeping one’s gloves on, even as the temperatures climbed into the high forties. The surface of a glacier does not resemble a frozen lake but is strikingly similar to a cheese grater, being formed of thousands of tiny, sharp-edged pits that efficiently rasp the skin from unprotected hands.
A much greater, but highly sporadic, threat arose from the boulders that would break free of their icy moorings and plummet down the face of the glacier. All afternoon we heard the rumbles and crashes of rocks that the sun had worked loose. A large section of the glacier was entirely covered in a shifting jumble of boulders, and others were eager to join their brethren. During lunch on our second day, I found a sunny spot alongside a stable boulder, which provided an effective barrier to the wind. From a couple hundred yards away, I heard a faint cry and saw Larry waving. I figured that he was coming to join me, so I waved back and shouted an invitation to lunch.
A few minutes later he came trudging up, shaking his head. “You never saw it, did you?” he asked.
My pithy reply, “Saw what?” answered his question.
“I wasn’t waving at you, I was warning you that a rock had broken loose.”
He had watched in horror as the stone, the size of a cooler, careened down the slope toward me but out of my line of sight. Having yelled my reply to him, I’d never heard it coming, and it had passed behind me before I knew it was there. “It couldn’t have missed you by more than ten feet,” he said. This was probably our closest brush with death in what was to be five years of expeditions.
After a lunch of dried apples, beef jerky, crackers, and M&Ms we went back to work, mucking rotten grasshoppers from the surface of the ice. We could find no whole bodies, but there were clumps of jumbled, decomposing corpses. In mats a couple inches thick and several square yards in area, the remains were like soggy peat moss—black, tangled masses of organic material. Amid the soft matrix, we could readily discern scraps of wings and broken legs. The most numerous parts were tiny jet-black mandibles, the hardest body parts of a grasshopper but
no larger than a typewritten v. There was another part in abundance, but for all our combined entomological expertise, we didn’t positively identify these until we returned to the laboratory. About the same size and shape as a typewritten H, these were fragments of the tentorium. Relying on a hardened shell-like cuticle for protection and support, insects don’t have an internal skeleton. However, the pressures that are generated by the powerful muscles controlling the grasshopper’s mandibles would collapse their heads without internal support. And so, the exoskeleton is involuted and forms bracing within the head; this support structure is called the tentorium. Most of the thin cuticle covering the body had been reduced to indistinguishable bits, littered throughout the soft, rotting tissues.
On our last day at the glacier, we scraped up as much soggy grasshopper gunk as we could from the patches that had surfaced. Then, Dick took charge of digging a series of three-foot-deep pits in search of embedded layers, for which he was rewarded with an exceptionally aerobic workout but no specimens. On the way back to camp, we hauled out nearly a hundred pounds of slushy organic debris. Larry, the workhorse of the team, carried half the load. Dick and I split the remaining Ziplock bags, as Tim’s energy was clearly ebbing. A diet of rehydrated foods, long hikes over shifting rock, cold nights on a lumpy meadow, and hard labor at more than two miles above sea level had taken their toll. After dinner that evening, Dick cleared his throat, pulled out a sample bottle of meltwater that he’d hauled down from the glacier, and with a grand flourish poured the contents into a flask that he extracted from one of the food boxes.
“To us!” he declared passing the concoction to me, “Twenty-year-old scotch and thousand-year old water—a fitting close to a successful expedition.”
Back in Cooke City, I was stretched out on a hotel bed after a luxuriously hot shower when Dick pounded on my door. “Check this out,” he said, handing me a black-and-white photograph. He’d met up with a local couple, Frank and Roberta Williams, who had lent him their family treasure—a photograph of the face of Grasshopper Glacier from 1900. This image was fully forty years earlier than any previous record of the glacier’s condition, and the implications were staggering. It was no wonder we’d found only decomposing remains of the locusts; in just a hundred years the glacier had dwindled to less than a twentieth of its past expanse. Where we had encountered a twenty-five-acre lake lapping at the toe of the glacier, there had once been an eighty-foot wall of ice towering over a small pond.
After returning to the laboratory, we dried the masses of debris and discovered that more than 90 percent of the sample was water, leaving us with less than a pound of material. And of this, a scant 2 percent was readily identifiable grasshopper remains—the rest being windblown dust, pebbles, and pulverized soft tissues of the insects. In a single glass flask we had some of the most valuable material ever mined from nature. With this jumble of dried grasshopper parts weighing in at about a quarter of an ounce, the cost of the flask’s contents worked out to nearly $30,000 a pound. But we had enough pieces to conduct radiocarbon dating, which placed the time of the locusts’ deposition at 800 years before the present. When medieval knights were jousting in Europe, a swarm of locusts had been swept up the valley and blown onto the ice. But could we be certain that these were the remains of the infamous Rocky Mountain locust?
Embedded within the contorted genitals of male grasshoppers are some hardened structures. When a grasshopper decays, the soft tissues rot and leave behind these oddly shaped pieces, a bit like the disarticulated skeletal remains that persist after a corpse decomposes. From these diagnostic structures, we knew that the remains belonged to the genus Melanoplus—and most likely to either sanguinipes or spretus. Based on a few hundred measurements of legs, wings, and other identifiable remains, the statistical balance tipped in favor of spretus. But without whole bodies from which intact genitalia could be studied, the identification could not be definitive. Moreover, the condition of the remains was such that there was little biological evidence that could be gleaned in terms of genetic or other molecular analyses.
Perhaps our scotch-and-water toast to “success” had been a bit premature. I had, however, learned a great deal about glacial prospecting for locusts. First, it was clear that, as we had suspected, this resource was rapidly disappearing. Indeed, we guessed that the exposed debris was the last of the preserved swarms. Our conjecture was based on having found no deeper layers of locusts and the fact that our radiocarbon dates were at the outer limits of those that Ashley Gurney had reported for the deep layers exposed at the foot of the glacier in 1952. If we were going to find well-preserved specimens of the Rocky Mountain locust, the clock was ticking and every passing summer meant that valuable material was rotting from the melting glaciers of the West.
Next, I had figured out what pieces of equipment and which supplies were actually needed for such ventures. Future trips would require far more lean and efficient logistics. Other sites were even less accessible, and the luxury of hauling gear in a truck was not likely to be repeated. Rather, we’d be backpacking a week’s worth of scientific and camp supplies into a remote site.
I also realized that a tremendous investment of resources and time could be negated by the vagaries of weather. We’d been lucky to have only a light snow, which melted within a day or two. But if a foot of snow had fallen, then we’d never have had a chance to see the surface of the glacier or find deposits of preserved insects. In these mountains, the time between the final melt of one spring’s snow and the first coating of the next autumn can be a matter of days. In some years the window is entirely closed. It was also clear that hauling a hundred pounds of slush to extract a few grams of locust parts was brutally inefficient. We had to find a method of extracting the needle without carrying the haystack back to the laboratory.
In light of the first expedition’s qualified success—we had, after all, managed to recover remains of what appeared to be the Rocky Mountain locust—I immediately sought funding for the next expedition. My contention was that we had to act quickly because an irreplaceable natural resource was melting from under us. A Cooke City resident told us of having seen whole bodies of locusts on the glacier just six years before our work. A review of various geological reports revealed that there were other glaciers in the Rocky Mountains that contained the remains of grasshoppers (or locusts), and because of their high elevations and northern exposures they had a good chance of still containing well-preserved specimens.
I gambled that this sense of urgency would parlay into funding. I lost the bet. Reviewers latched onto the rotten state of affairs at Grasshopper Glacier instead of the possibility that other sites would be in better condition. Rather than interpreting our findings as cause for an emergency intervention to preserve a dwindling resource, my colleagues took the proposal as an obituary. Once again, I had to beg for some meager funding from my own institution, rather than partake of the riches of the National Science Foundation. However, my harshest lesson came when we attempted to publish our findings from this first expedition.
In 1988, we submitted a paper describing what we had found, including the condition of the glacier, the location of deposits, the types of insect parts we had extracted, the radiocarbon dating, and the analyses that had led us to believe we had recovered the remains of the Rocky Mountain locust. As it was the first report of such a study in nearly fifty years, we hoped that the manuscript would be well received. It was rejected. The editor of Environmental Entomology at that time explained that the study did not constitute a controlled experiment. I wondered where we were supposed to find a “control glacier” and what experiment could have been done if we had located such a resource. My written appeal to the editorial board—the only time I have ever been brazen enough to take such a step—was denied with the incisive summary, “You have mistaken natural history for science.” It seems that replication, statistical design, and controlled experimentation defined science, at least at that time, for the entomological community. Th
is view suggested that initiatives such as the Human Genome Project (decidedly lacking a clear hypothesis), the entire field of cosmology (there is, after all, only one universe), and entire projects devoted to unreplicated discovery (NASA’s deep space probes) were not science. It was as if nothing of value was left to describe in the natural world—a remarkable position for entomology, a field in which no more than a tenth of the fundamental units of study (insect species) are even known.
Still more disturbing was the notion that science required manipulation of the natural world, rather than patient observation or thoughtful description. The Rocky Mountain locust was gone, and no experiment will ever show the course of events that led to its demise, explain the role it played in western ecosystems, or reveal what other species may have perished along with it. Its tale would be told, if at all, to those willing to listen rather than to those demanding answers. In the end, the paper was published in American Entomologist —a semipopular journal without the technical rigor and prestigious status of Environmental Entomology—and I received more reprint requests for it than I have for any paper that involved a controlled experiment. Maybe this response was because I do not develop very interesting experiments, or perhaps because even scientists find value in stories and marvel at the tale of the Rocky Mountain locust.
Most important, this conflict solidified in me a personal passion to find unimpeachable evidence of glacially preserved Rocky Mountain locusts, to bring back a whole body of this magnificent creature to prove that my idea of their having been preserved somewhere among the peaks of their homeland was not a quixotic flight of fancy. I bridled at my colleagues’ suggestions that the search for the last bodies of spretus was in vain. I was thirty years old and still had the belligerent defiance of my youth—a quality that was both a wellspring of internal drive and an occasional source of unnecessary conflict. I could appreciate Riley’s passion and for me, nothing was so motivating as to be doubted, even mocked (as would happen in later reviews of my work). The gauntlet had been thrown down, and my expeditions to the glaciers of the Rocky Mountains became a search for a lost locust—and for professional pride.
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