Geology and Geography

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Geology and Geography


The Fur Trade. Fur trappers, or mountain men as some people called them, while not scientific or government explorers, gathered empirical information that aided the soldiers and naturalists who followed them. Either learning from Indians or on their own, trappers discovered the courses of river systems and the locations of critical passes as well as the scarcity or abundance of game in particular regions. Manuel Lisa launched an expedition in 1807 that explored the tributaries of the Upper Missouri River, seeking a mountain route to the Spanish settlements of Taos and Santa Fe. One of Lisas employees, John Colter, a former member of Meriwether Lewis and William Clarks Corps of Discovery, delivered reports of a beautiful area known today as Yellowstone National Park. Following Mexican independence from Spain in 1821, American traders explored the mountains of the Southwest, seeking alternative trade routes. A party led by Etienne Provost in 1825 crossed the Uinta mountain range in northeastern Utah and located the Great Salt Lake, never before seen by whites. The following year Jedediah Smith directed an expedition that left Utah and followed the Adams River to the Colorado below the Grand Canyon. From there Smiths party followed an ancient Indian trail into the Mohave Desert, becoming the first citizens of the United States to cross the Southwest into the Spanish settlements of California. Traders such as Smith, while pursuing profit more than science, nevertheless shared their findings with government agents, sending a steady flow of knowledge eastward that excited ethnographers and naturalists.

First View of the Rockies

On 15 November 1806 Zebulon Pike recorded his first observation of the Rocky Mountains near the present-day site of Lamar, Colorado. Pikes description indicates both his natural appreciation for their grandeur and his curiosity about the Rockies hydrological and even political importance.

At two oclock in the afternoon I thought I could distinguish a mountain to our right, which appeared like a small blue cloud. Viewed it with the spy glass and was still more confirmed in my conjecture, yet only communicated it to Doctor Robinson, who was in front with me, but in half an hour they appeared in full view before us. When our small party arrived on the hill they with one accord gave three cheers to the Mexican mountains. Their appearance can easily be imagined by those who have crossed the Alleghanies; but their sides were whiter, as if covered with snow or a white stone. Those were a spur of the grand western chain of mountains which divides the waters of the Pacific from those of the Atlantic Ocean, and it divided the waters which empty into the bay of the Holy Spirit from those of the Mississippi as the Alleghanies do those which discharge themselves into the latter river and the Atlantic. They appear to present a natural boundary between the provinces of Louisiana and New Mexico, and would be a defined and natural boundary.

Source: Zebulon Montgomery Pike, The Southwestern Expedition of Zebulon M. Pike, edited by Milo Milton Quaife (Freeport, N.Y.: Books for Libraries Press, 1970), pp. 70-71.

Maps. At the beginning of the nineteenth century the most accurate picture of Western North America derived from a 1795 map that mistakenly showed several inland

lakes, considerably larger than the Great Salt Lake, that cartographers probably included from vague reports they had received from Indians. In 1806 John Cary produced a map that accurately depicted the Pacific coastline, but he wisely refrained from presenting undocumented inland features. As a result he left blank almost the entire region west of the Mississippi. The expeditions of Lewis and Clark and Henry Schoolcraft, who explored the Upper Mississippi in 1820, produced two new maps in 1818 and 1826 respectively, but neither of these new maps accurately represented the country west of the Rockies with any real precision. In 1836 Albert Gallatin compiled a superior mapbased on the findings of Smith and othersthat depicted the Great Basin, the waterways of California, and the course of the Colorado River. The popularity of Gallatins work, however, paled beside a map published the following year by Capt. Benjamin Louis Eulalie de Bonneville. Advertised extensively by Washington Irving, Bonnevilles map depicted the complete hydrography of the region west of the Rockies. He determined the extent, direction, and sources of several major rivers including the Sacramento and San Joaquin. Until the Fremont-Preuss map of the 1840s, Bonnevilles map remained dominant, even though he repeated many findings already located in Gallatins map. In 1854 G. K. Warren compiled all known research from the previous half-century to produce an exhaustive map of the United States from the Mississippi to the Pacific. Geographers concur that Warrens publication marked the official end of geographic exploration and the beginning of a new research stage: the detailed survey, which John Wesley Powell pioneered in the 1870s.

Topographical Engineering. During the War of 1812 the federal government created a unit of topographical engineers to survey and make plans for all military positions and routes. After 1816 the unit reconnoitered several routes in the Old Northwest, surveyed the Santa Fe Trail, and supervised many internal improvements such as the Chesapeake and Ohio canal and the Cumberland Road. Their successes led to the official establishment of the U.S. Army Corps of Topographical Engineers in 1838, which conducted the first geological explorations of the American West. For instance, Howard Stansbury surveyed the Great Salt Lake, finding evidence of an ancient shoreline that indicated a formerly more extensive lake at least eight hundred feet above the modern one. In the 1850s the Pacific Railroad conducted several surveys in the far Northwest. Pursuing Lewis and Clarks observations that Mount St. Helens in present-day Washington State had erupted in 1802, railroad geologists studied the effects of ancient volcanic processes on shaping the Northwestern terrain. In 1857 J. S. Newberry, a geologist for the Pacific Railroad, investigated shell beds and alluvial plains on the West Coast and inferred that the Oregon Cascades once had been covered by an ice cap. The findings of geologists and engineers in this early period, built on the reports of earlier explorers and Indian tribes, launched an ongoing study into the geological origins of North America.

Theoretical Challenges. Beginning in the late eighteenth century naturalists turned considerable attention to the New World and hoped, through the growing knowledge of geophysical sciences, to complete an inventory of the entire planet. Decades later natural scientists and surveyors pursued these goals with renewed vigor following the United Statess conquest of the Southwest. In the 1850s the U.S. Coast Survey undertook a thorough exploration of the Pacific coast, while scores of private agencies located and identified the major plant and animal species of California. This work influenced scientists thinking on a number of issues. Many had studied under Louis Agassiz, noted for his studies of glaciation and his rejection of Charles Darwins evolution theory. Therefore North American scholars often agreed with Agassiz in rejecting Darwinian views about natural selection. Yet surrounded by fossil evidence of a prehistoric past, others did come to believe in a subtle form of evolution theory where species transmute gradually. They supported their views by pointing to the diversity of ecosystems in California, asserting that the ocean once had extended to the Sierra Nevada mountain range and that prehistoric seas had shaped the lands major contours.

Trask and Condon. John Boardman Trask, a San Francisco physician, conducted several geological and agricultural excursions into the Sierra Nevada, gaining a reputation as Californias first unofficial state geologist. Arriving in California in 1849, Trask collected and catalogued numerous plants, rocks, and fossils and produced an extensive mineral district map that outlined the states agricultural and mining potential. Several of his mid-1850s reports suggest that the Pacific Ocean had once extended far inland and then receded. These theories encouraged later paleontological surveys. In Oregon the geologist Thomas Condon, best known for exploring the John Day Fossil Beds, collected a variety of Cretaceous and Tertiary fossils, which led him to support the Development Theory (as evolution was then known). In doing so Condon, who also served as a congregational minister, supported a theory quite radical for its time. Condon also located evidence of a three-toed horse, strengthening theories of animal evolution. He made geologic observations of the Columbia River gorge. Trask and Condon are only two examples of the many Western scientists who, isolated from the institutions and financial support of the Atlantic Coast, turned to the vast outdoor laboratory around them. Like the government surveyors who accompanied them, they learned the importance of firsthand field observation and pushed American science forward.


E. W. Gilbert, The Exploration of Western America, 18001850: An Historical Geography (New York: Cooper Square, 1966);

Alan E. Leviton, Peter U. Rodda, Ellis Yochelson, and Michele L. Aldrich, eds., Frontiers of Geological Exploration of Western North America (San Francisco: Pacific Division of the American Association for the Advancement of Science, 1982);

Michael L. Smith, Pacific Visions: California Scientists and the Environment, 18501915 (New Haven: Yale University Press, 1987).

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