The Great Falls of the Missouri River are a series of waterfalls on the upper Missouri River in north-central Montana in the United States. From upstream to downstream, the five falls, which are located along a 10-mile (16 km) segment of the river, are:
The Missouri River drops a total of 612 feet (187 m) from the first of the falls to the last, which includes a combined 187 feet (57 m) of vertical plunges and 425 feet (130 m) of riverbed descent. The Great Falls have been described as "spectacular", one of the "scenic wonders of America", and "a major geographic discovery". When the Lewis and Clark Expedition became the first white men to see the falls in 1805, Meriwether Lewis said they were the grandest sight he had beheld thus far in the journey.
The Great Falls of the Missouri River were depicted on the territorial seal of the Montana Territory, and later on the state seal of Montana in 1893.
The Mandan Indians knew of cataracts and called them by a descriptive (but not formal) name: Minni-Soze-Tanka-Kun-Ya, or "the great falls." The South Piegan Blackfeet, however, had a formal name for Rainbow Falls and called it "Napa's Snarling." No record exists of a Native American name for any of the other four waterfalls.
Four of the five waterfalls were given names in 1805 by American explorers Meriwether Lewis and William Clark. Both Lewis and Clark named Crooked Falls in their journals. Clark named three of the remaining waterfalls on his map: "Great Falls" (which retains its name to this day), "Beautiful Cascade" (now called Rainbow Falls), and "Upper Pitch" (now known as Black Eagle Falls). "Beautiful Cascade" was renamed "Rainbow Falls" in 1872 by Thomas B. Rogers, an engineer with the Great Northern Railway. Colter Falls received its name from Paris Gibson, in honor of John Colter (a member of the Lewis and Clark Expedition). Black Eagle Falls is named for the black eagle which built a nest in a cottonwood tree on an island in the middle of the falls. It is not clear when the falls lost their original name of "Upper Pitch," but they had acquired their modern name by at least 1877.
The Missouri River lies atop the Great Falls Tectonic Zone, an intracontinental shear zone between two geologic provinces of basement rock of the Archean period which form part of the North American continent, the Hearne province and Wyoming province. Approximately 1.5 million years ago, the Missouri River, Yellowstone River and Musselshell River all flowed northward into a terminal lake. During the last glacial period, the Laurentide and Cordilleran ice sheets pushed these lakes and rivers southward. Between 15,000 and 11,000 BCE, the Laurentide Ice Sheet blocked the Missouri River and created Glacial Lake Great Falls. About 13,000 BCE, as the glacier retreated, Glacial Lake Great Falls emptied catastrophically in a glacial lake outburst flood. The current course of the Missouri River essentially marks the southern boundary of the Laurentide Ice Sheet. The Missouri, Yellowstone and Musselshell rivers flowed eastward around the glacial mass, eventually settling into their present courses. As the ice retreated, meltwater poured through the Highwood Mountains and eroded the mile-long, 500-foot-deep (150 m) Shonkin Sag—one of the most famous prehistoric meltwater channels in the world.
The Great Falls themselves formed on a fall line unconformity in the Great Falls Tectonic Zone. The Missouri River settled into a bedrock canyon which lay beneath the clay laid down by Glacial Lake Great Falls. The course of the Missouri in and around the Great Falls has changed very little since then, in comparison to lower regions of the river on the ground moraine that forms much of the upper Great Plains.
The Great Falls of the Missouri River formed because the Missouri is flowing over and through the Kootenai Formation, a mostly nonmarine sandstone laid down by rivers, glaciers, and lakes in the past. Some of the Kootenai Formation is marine, however, laid down by shallow seas. The river is eating away at the softer nonmarine sandstone, with the harder rock forming the falls themselves. Until relatively recently (in geologic time) the Missouri River in the area had a much wider channel, but it has now settled into its current course, where it will continue to cut more deeply into the sandstone.
The first human beings to see the Great Falls were Paleo-Indians who migrated into the area between 9,500 and 8,270 BCE. The earliest inhabitants of North America entered Montana east of the Continental Divide between the Cordilleran and Laurentide ice sheets. The area remained only sparsely inhabited, however.Salish Indians would often hunt bison in the area on a seasonal basis, but no permanent settlements existed near the Great Falls for much of prehistory. Around 1600, Piegan Blackfoot Indians, migrating west, entered the area, pushing the Salish back into the Rocky Mountains and claiming the area as their own. The Great Falls of the Missouri remained in the tribal territory of the Blackfeet until Americans claimed the region in 1803.
Although the discovery of the Great Falls by Native Americans is not recorded, the South Piegan Blackfeet were well-acquainted with the Great Falls by the late 18th century, and news of the cataracts had spread among native peoples as far east as central North Dakota.
The United States purchased the area around the Great Falls of the Missouri from France (which claimed the area despite Native American habitation) in 1803, as part of the Louisiana Purchase.Thomas Jefferson, then President of the United States, had long desired to send an expedition into the area. Jefferson sought and won permission and funding for an expedition from Congress in January 1803. On May 14, 1804, the Lewis and Clark Expedition departed St. Louis, Missouri to map the course of the Missouri River; establish whether a river route to the Pacific Ocean existed; study the Indian tribes, botany, geology, terrain and wildlife in the region; and evaluate whether British and French Canadian hunters and trappers in the area posed a challenge to American control over the region. Expedition leaders Meriwether Lewis and William Clark first learned of the "great falls" from the Mandan Indians while wintering at Fort Mandan from November 2, 1804, until April 7, 1805.
The Lewis and Clark Expedition reached the Great Falls on June 13, 1805. Meriwether Lewis was the first White person to see the falls. Lewis described the encounter in a now-famous passage of his expedition diary:
The falls which Lewis had seen were the lowest of the five falls, the Great Falls. Exploring the following day, Lewis discovered Crooked Falls, Rainbow Falls, Colter Falls, and Black Eagle Falls. At the final waterfalls, Lewis saw an amazing sight:
Mounting a hill near Black Eagle Falls (probably where the town of Black Eagle is today), Lewis saw that the cataracts ended and that another large river joined the Missouri about two and a half miles further upstream. Although it was very late in the afternoon, Lewis rushed forward to see this river and was attacked by a grizzly bear. He ran more than 80 yards and launched himself into the Missouri River, and luckily the bear did not follow. The Lewis and Clark Expedition was forced to portage around the Great Falls, an arduous task that took nearly a month.
York, an African American slave owned by William Clark and who had participated in the Expedition, was the first black American to see the Great Falls.
The Lewis and Clark Expedition made a number of discoveries near the Great Falls. On June 13, Silas Goodrich caught numerous Westslope cutthroat trout at the falls, the first time anyone in the expedition had seen these fish, and several samples were preserved which constituted the type specimens for the fish. The trout was subsequently given the scientific name Oncorhynchus clarki lewisi in honor of the expedition leaders. The Westslope cutthroat is now the "official state fish" of Montana. The explorers also collected the first samples of the gumbo evening primrose and western meadowlark at the Great Falls.
On June 18, while reconnoitering the series of falls on the south side of the Missouri River with a group of five others, William Clark discovered Giant Springs, which he correctly judged to be the largest spring in the world. He was the first white person to see the springs, and the first white person to see the falls from the south side of the Missouri.
Meriwether Lewis revisited the Great Falls on July 11, 1806, as the Corps of Discovery returned east. Lewis and nine men stopped at the Great Falls with the intention of exploring the Marias River and discovering its source. But during the night, Indians stole half the party's 17 horses, forcing three of the men to stay behind.
Following the return passage of Lewis and Clark in 1805/06 there is no record of any white man visiting the Great Falls of the Missouri until explorer and trapper Jim Bridger reached them in 1822. White people next visited the Great Falls when Bridger and Major Andrew Henry led a fur-trading expedition there in April 1823 (and were attacked by Blackfeet Indians while camping at the site). British explorer Alexander Ross trapped around the Great Falls in 1824. In 1838, a mapping expedition sent by the U.S. federal government and guided by Bridger spent four years in the area. Margaret Harkness Woodman became first white woman to see the Great Falls in 1862.
The first permanent settlement near the Great Falls was Fort Benton, established in 1846 about 40 miles (64 km) downstream from the Great Falls. The Great Falls marked the limit of the navigable section of the Missouri River, and the first steamboat arrived at the falls in 1859. In 1860, the Mullan Road linked Fort Benton with Fort Walla Walla in the Washington Territory.
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