Three hundred years after the Voyage of Discovery, the findings of Lewis and Clark are still affecting our everyday lives.

By Gary Lantz

Mapping: From Octant to GPS

Lewis and Clark's Corps of Discovery set off from St. Louis in May 1804, charged by President Thomas Jefferson with exploring the recently acquired Louisiana Territory and finding the Great River of the West, a fabled water route to the Pacific. The president specifically requested maps of the territory; only the general shape of the continent was then known. Trained as a surveyor in the Army, William Clark produced most of the 140 maps made during the voyage. Another 30 were collected from fur trappers, traders, and Native Americans. As Ralph Ehrenberg describes in his book Route Mapping on the Lewis and Clark Expedition, Clark produced four types of maps: large-scale compass traverse maps, which showed each day's route; smaller sketch maps in his journal; copies of maps from traders and Native Americans; and two composite maps of the West. Measurement techniques in the early 1800s were refined manual skills, as opposed to today's digital data collection, in which computers measure and automatically sort and plot data. Clark used celestial observation to determine latitude, triangulating position with an octant. The expedition carried a chronometer for measuring longitude, although winding it each day at noon was a challenge. Distance over land was measured in miles, estimated by the experienced woodsmen. When Clark needed more accurate measurements, he employed a "two-pole chain," an aptly named surveying tool measuring 33 feet between poles. When traveling by water, the expedition measured distance and speed with a "log line reel," a knotted rope, which they let out then timed how long it took to play out. For direction, they used a simple surveyor's compass. Despite the many possibilities for error, the resulting maps were relatively accurate, at least in shape if not scale. And they proved to be a good benchmark, opening the way for more detailed exploration and surveying in the centuries that followed. Cartography has come a long way, of course, since that history-making journey. Advances in surveying and later in aerial photography led to more accurate maps in the early 1900s. When satellites began orbiting the earth in the 1950s, it became possible to create a highly accurate digital map of the earth's surface. In 1972 NASA launched the first Landsat satellite, which measured the landcover of the entire globe. Since then, an increasing number of satellites have collected data for mapping applications worldwide. At American Forests, natural features are mapped along with built structures such as parking lots and buildings. The urban forestry department works with communities to map both natural and built portions of a community. Instead of a chronometer, American Forests relies on data collected by others, including satellite and aerial imagery, and a technology called Geographic Information Systems (GIS). A GIS project analyzes images using georeferenced data, data such as rainfall numbers, tree canopy percentages, or population figures with a latitude and longitude. Because any point on the earth can be georeferenced, all sorts of data can be overlaid on a base map to show the spatial and causal relationships between the layers. Instead of compasses, octants, and two-pole chains, modern digital GPS units determine position and direction. In addition to the geological features recorded by Lewis and Clark, GIS mapping technology can detail living systems, such as tree canopy. Where Lewis and Clark's maps showed only the features they could discern, GIS maps use digital layers to overlay data from a variety of sources. Data such as population density numbers can be displayed along with tree canopy coverage. And while Clark's maps were a snapshot of the territory, modern GIS maps can show changes over time. By using tree cover data over several decades, American Forests can map tree cover changes over time and then analyze that change using its CITYgreen software. As the GIS's supporting data is updated, the map is automatically updated as well. That's much better than having to redraw the map by hand. William Clark's maps, tremendously valuable in their day, are still a priceless piece of history. Yet modern GIS technology is transforming cartography from a static, representational science into a dynamic systematic approach to understanding the world. One of the celebrations of the Lewis and Clark bicentennial is a GIS project to map historical data collected during the voyage. Up until now that data has never been displayed in a visual format. Imagine what William Clark, octant in hand, would say to that.-Claiborne Walthall

When Thomas Jefferson sent Meriwether Lewis and William Clark to explore the uncharted West, he set in motion actions which even today affect how we manage our forestlands. In this issue of American Forests, we look at some of those connections, including a closer look at some of the trees Lewis and Clark identified and brought back East. Among them were species like ponderosa and lodgepole pine, trees that proved so commercially valuable they contributed significantly to the building of the country. Those trees continue to influence American Forests' ecosystem restoration projects as we strive to plant damaged lands with beneficial native species. In fact, some of the national champions of those species still grow along or near the explorers' route. And some of the trees on the route have historical status, having borne witness to the events of 300 years ago.

The maps meticulously drawn by William Clark were a forerunner to the maps we use today, although the differences between them are vast. While Clark's maps detailed their route and latitude and longitude, allowing people to travel from place to place, cartographers today can combine satellite technology with sophisticated computer programs that allow them to map out courses of action that would achieve sought-after outcomes. For example, with the technology available today, it's possible to see how the danger of erosion would be lessened along a streambank if a certain number of trees were planted there.

Perhaps the most interesting correlation between Lewis and Clark's journey and the world today is the working together of peoples from different cultures. Lewis and Clark were successful in part because of the Shoshone woman Sacajawea, who joined the expedition with her husband Toussaint Charbonneau, a hired interpreter. Today that same reaching out across cultural and interest boundaries can be seen in the community-based forestry movement, where locals at the edge of the public forests work with agency officials, businesses, and environmental groups to find common ground on the best way to manage the forest.-The Editors

Before Lewis and Clark, the territory west of the Mississippi River was about as well understood as outer space-almost as mysterious as the Americas were to Christopher Columbus the day he dropped anchor off El Salvador.

It was home to the red nations, yet an enigma to recently arrived whites. French and Spanish traders made inroads along the major waterways, yet little was known of this vast slice of continent other than rumors that blended a dash of speculation with boundless exaggeration. It was our very own African heart of darkness, with a handful of men proceeding cautiously upriver to obtain furs from the various native tribes . . . and courting death in the process.

At the time President Jefferson himself entertained notions that fabled creatures like woolly mammoths might still live in the huge wilderness he had recently claimed with a stroke of his pen. Traders told of large Indian villages up the Missouri River, and in fact the Mandan village where the Lewis and Clark expedition first wintered was actually larger than the city of St. Louis then.

Contemporary folklore regaled listeners with beyond-the-Mississippi tales of blue-eyed Indians speaking a Welsh dialect and of an endless sweep of erupting volcanoes, huge mountains of salt, 7-foot-tall beavers, buffaloes with slim waists and cheerful demeanors, and of course unicorns.

Then in 1803, they suddenly became our unicorns, another American original if someone dared venture forth to document it. That venturing was left up to captains Meriwether Lewis and William Clark-a pair of Virginians with a knack for leadership and equal parts raw courage and inquisitiveness-to face the unknown and make a full report.

Jefferson ordered Lewis and Clark to assemble a crew to explore the 820,000 square miles of newly acquired U.S. territory. His faith in these two officers would be rewarded with exemplary performance. Clark was known for his ability to "build forts, draw maps, lead pack trains through enemy territory and fight Indians on their own ground." Lewis exhibited a cool ability to command during times of crisis along with a flair for natural history. Both were superb outdoorsmen.

The two officers assembled 31 men, saw to their training, and accumulated supplies as instructed. On May 14, 1804, the crew that would come to be known as the Corps of Discovery raised the sails on its keelboat and began the official exploration of the American West. During the next three years the crew would face challenges akin to a modern day trip to the moon. Lewis and Clark's reports erased a number of physical and psychological barriers to a region that would eventually shape the nation's character while yielding a large percentage of its natural resources and wealth.

Even as the expedition forced its way through the territory of hostile tribes, both Lewis and Clark managed to keep the objective of the undertaking in focus. Theirs was a scientific mission, and the men dutifully collected the life forms they encountered, including at least 178 plant species previously unknown to science.

It is difficult for many of today's westerners to comprehend that, before Lewis and Clark, the nation had no knowledge of prairie dogs nor grizzly bears, did not know of now-familiar plants, including big sagebrush and prickly pear cactus.

The Corps of Discovery's crew would be among the first white men to gaze upon species that we now consider common, including Ponderosa and lodgepole pine. The expedition would collect and describe Pacific yew and prairie rose, and even that home remedy rage of our age, Echinacea angustifolia, or purple coneflower.

Among the expedition's discoveries was a tree common to Plains Indian's sacred rites, a tree that supplied fuel along sparsely timbered rivers, shade in scorching summers, roosts for turkeys, critical nesting habitat for a variety of songbirds, emergency rations for horses in winter, and wood for drums and even canoes.

That tree, the plains cottonwood (Populus deltoids occidentalis), proved critical to the survival of nomadic Indians and later the settlers who eventually shoved native Americans out of the western river bottoms that provided wild game for food and grass for ponies. Today cottonwoods can still be found from Manitoba down through the central plains to Texas. The species continues to comprise the bulk of wildlife habitat along western waterways, although flood control projects, depleted water tables, and the presence of invasive alien species have all hampered healthy natural recruitment.

Farther west, the Lewis and Clark expedition first encountered Cornus nuttallii, the Pacific dogwood. Like eastern dogwood varieties, the western version is a species noted for the density of its wood and its ability to fill a sizable ecological niche in Pacific coastal woodlands.

Pacific dogwood grows along the coast in a strip several hundred miles wide. It's generally part of understory vegetation in association with spruce, cedar, hemlock, Douglas-fir, red fir, redwood, and even certain pine and oak shrublands. A shade-tolerant species, it's sometimes harvested for the heads of golf club, piano keys, and textile shuttles. Although high in tannin, the tree supplies fruits relished by several species of birds; its new shoots are browsed by deer. Pacific dogwood also is an excellent streambank stabilization plant.

Another shrubby Pacific coast original first noted by Lewis and Clark is Pacific yew (Taxus brevifolia). The wood from the yew makes excellent bows; the tree itself can form a dense understory in association with spruce and fir. The plant offers excellent moose browse. Several species of birds flock to gather the fruit.

Medical professionals applaud the healing properties of Taxol, a drug obtained from the bark of Pacific yew. Taxol has been successful in limiting the growth of cancer cells, and chemists are striving to synthesize the substance. At present, Pacific yew yields more Taxol than any other species.

Some of the most beautiful scenery in the West is created thanks to another species recorded by the Corps of Discovery. Outcrop islands of Pacific ponderosa pine (Pinus ponderosa var. ponderosa) merges with high-altitude grasslands in a look made famous by directors like John Ford and immortalized as a backdrop for legendary actors including John Wayne.

The majestic ponderosa pine occupies the transition zone between mountain valleys and the cooler, damper spruce/fir zone. Ponderosa oftentimes forms open, park-like savannahs with evenly spaced trees surrounded by grasses. A valuable lumber tree, it's also considered an important tree for wildlife, which depend on it for food and habitat.

Lodgepole pine (Pinus contorta var. latifolia) was the Plains tribes' favorite source of structural support for tipis. The tree can be found growing in mountains from Canada to the Colorado border, from grassy foothills into the spruce/fir zone. In portions of Yellowstone National Park and similar environs, lodgepole pine forms nearly solid stands. Lewis and Clark actually bypassed Yellowstone and all its geysers, a place even more magical in reality than the vast realm of smoking volcanoes rumored pre-expedition to be waiting in the West. Corps of Discovery member John Colter left his fellow explorers in the final weeks of the journey to stay in the wilderness and trap beaver. Colter's travels would take him through the fantastic Yellowstone landscape. The mountain man memorized all that he witnessed, and later related his findings to civilized folks back home, who derided the landscape he described as "Colter's Hell."

Bigleaf maple (Acer macrophyllum), is also a tree of the damp Pacific Coast, and there is little doubt that the expedition would have come to know this species well as they waited out the long, wet winter upon reaching the ocean. Rain fell almost every day the men were encamped and the expedition suffered both from sickness and depression, enough to literally dampen any enthusiasm for the cold, foggy, and sodden environment that kept the men confined while they longed for the return trail.

Bigleaf maple can form pure stands along streams, and forms a component of mixed forests including Douglas-fir, Sitka spruce, western hemlock, redwood, black cottonwood, willows, alders, ash, aspen, willows and a variety of western oaks and pines. The tree is commercially valuable and used for furniture veneer, musical instruments and paneling. Small trees provide browse for deer while seeds, buds, and flowers feed songbirds and small mammals. As with any maple, Acer macrophyllum is a delight to behold in its natural state, and it was certainly in a very natural state when first beheld by Lewis and Clark.

These are but a few of the plant species first described by the Corps of Discovery, a sampling of an amazingly varied list. Information included in the expedition's journal notes spread like a new religion among fellow naturalists, who felt as if an entire new universe was now open to them. Many soon headed West themselves, driven by curiosity and the scientific challenge of limitless life forms awaiting just beyond the realm of the imagination in this new, and suddenly much larger and more interesting, United States.

Lewis and Clark's scientific discoveries truly gave birth to an era of scientific exploration much like the epic cataloging and classifying that has taken place in the rainforest during past decades. Almost overnight the West became an Eden for plant hunters, each in debt to the Corps of Discovery for unlocking what had been, just years before, a sinister yet intriguing gate. AF

Gary Lantz writes from his home in Norman, Oklahoma. [TOP]