Boundaries
by Jack Nisbet

Jack Nisbet is the author of The Mapmaker's Eye, Sources of the River, Purple Flat Top, Singing Grass, Burning Sage and Visible Bones. His newest, The Collector, is due out in October.

One Tooth, Many Bones
January 2009

            During the early days of Chewelah’s Northwest Magnesite Company, just after World War I, a worker at the Red Marble Quarry picked up a strange object about the size of a large human foot. Among chunks of marbleized dolomite, it felt like real ivory. Composed of sixteen rectangular plates sandwiched together, the curiosity was worn to the base on one end and to the fourth plate on the other. When the discoverer showed it around to his fellow workmen, someone recognized it as a mammoth molar, and by 1920 the tooth had been donated to the Northwest Museum of Arts and Culture, where it has resided ever since. All by itself, this artifact proved that at some point in past mammoths cavorted in the Colville Valley, and so played a major role in inspiring the Keith Powell-David Govedere mural the graces the Chewelah city hall today.
            But what else does that molar tell us? Over the past hundred and fifty years, large bones have stirred local excitement around small towns throughout the Pacific Northwest. Sea captains have stumbled across skulls on beaches, children have pulled molars out of eroding cliffs, farmers have piled up remains of multiple mammoths while draining wetlands, backhoe operators have scraped long ribs while digging trenches. People love to touch such artifacts, to have their pictures taken alongside them, to revel in the fact that something monstrous and awe-inspiring was buried in their own back yard. After that initial spark, however, the excitement usually dies away. Most of the bones and teeth end up in barn lofts or on dark museum shelves, while the magical tales about the animals they represented, and the world they were a part of, fade away.           
            Over the last couple of decades, some dedicated amateur and professional sleuths have been trying very hard to expand these aspects of the story. After a considerable cache of mammoth bones emerged from the mud of a drained Tolo Lake in the 1990s, the nearby town of Grangeville, Idaho, authorized the construction of a full-sized replica mammoth that greets visitors as they drive south on Highway 95. When a road construction crew unearthed large bones along Wenas Creek, near Selah, Washington, in 2005, the landowners contacted a professor at Central Washington University in Ellensburg; in the summers since, organized digs involving school teachers and students have turned the site into a model of outdoor education. Most recently, a promising strike outside Kennewick has attracted the attention of media across the region. An educational institute has been set up, and professional diggers and data loggers have settled in for a patient long exploration of every facet of the site. While many of the early mammoth discoveries were carried out in a flurry of public excitement, the quote most often associated with the Wenas Creek and Kennewick finds has been a reassuring “We’re in no hurry.”
George Last, a geologist who has been associated with the Pacific Northwest National Laboratory in Richland for years, typifies this new approach. Last has a long-term interest in the relationship of wind-blown soil deposits to the Ice Age Floods from Lake Missoula, which tore through much of our region roughly between 20,000 and 13,000 years before the present. In his work, Last has focused on ice age flood features in Southeast Washington in general and the Pasco Basin in particular.
A few years ago George Last started wondering if he could help mount a systematic approach to the question of what happened to all the large Ice Age mammals — animals such as mammoths, mastodons, camels, ground sloths, horses, bison, dire wolves, bone-eating dogs, and large-toothed cats ­-- that were present during the time of those floods and disappeared entirely around 10,000 years ago. Certainly those in any torrent’s direct path would have been drowned, but mammal bodies tend to float, and often end up coming to rest in backwater eddies just off the main course of flow. Last and others have spent years charting the maximum water level of Lake Lewis, the temporary body of water that filled the Pasco Basin during those Ice Age Floods. Ice-rafted erratic rocks show that Lake Lewis crested between 1000 and 1250 feet above sea level during its various incarnations.
When Last started plotting known finds of mammoth remains in southeast Wasington against that maximum lake level, about forty sites hit near the high-water mark. Since 2005, Last has added a couple of dozen more, and spent a lot of time wondering what they all might mean. "I mean what good is a single bone?" Last says. "Just one small clue about one individual mammoth. What we want to know now is the entire context of each find. We want to understand how the Columbia mammoth lived its life, and see the environment that helped them thrive. We want to think about what changed to cause their extinction."
To help achieve these ends, Last is developing a data catalog for each mammoth find in southeastern Washington. The more story he can tease out of each discovery, the more it can be used to help students see the larger picture. So far, he has six or eight sites that really have something to say.
In May of 2007, Last was called to a hilltop site outside Kennewick where some large bones had come to light. The elevation of the hilltop was around 1000 feet; the maximum level of the Ice Age Floods in that particular area runs about 1250 feet. The bones Last looked at were disarticulated, but in close proximity, and fairly well fossilized. After a day and a half of exploring, he was able to determine that the material around the bones consisted of fine-grained Ice-aged flood deposits. Although Last and others have looked carefully, no one has yet found any volcanic ash markers or clean exposures that might provide a more exact date for the burial. This does not distress him at all.
An experienced team of experts from Central Washington and UW in Seattle is systematically working the hilltop. The landowners have formed an educational institute that will allow students from the Tri-Cities and beyond to visit the dig and work as volunteers when needed. The story of the Kennewick site, and of how mammoths fit into the complex world of the Intermountain West during the last Ice Age, is only beginning to unfold. When the next strange tooth tumbles down from the Huckleberry Mountains, or erodes out of some bank on Lake Roosevelt, it will immediately become part of this larger context, and be able to tell us something new.
           

Illustration: mammoth molar by Emily Nisbet

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