Rocky Mountains in the context of "Pierre Shale"

The Mississippi River is the primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri. From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for 2,340 mi (3,770 km) to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky and Appalachian mountains. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana. The main stem is entirely within the United States; the total drainage basin is 1,151,000 sq mi (2,980,000 km), of which only about one percent is in Canada. The Mississippi ranks as the world's tenth-largest river by discharge flow, and the largest in North America.

Native Americans have lived along the Mississippi River and its tributaries for thousands of years. Many were hunter-gatherers, but some, such as the Mound Builders, formed prolific agricultural and urban civilizations, and some practiced aquaculture. The arrival of Europeans in the 16th century changed the native way of life as first explorers, then settlers, ventured into the basin in increasing numbers. The river served sometimes as a barrier, forming borders for New Spain, New France, and the early United States, and throughout as a vital transportation artery and communications link. In the 19th century, during the height of the ideology of manifest destiny, the Mississippi and several tributaries, most notably its largest, the Ohio and Missouri, formed pathways for the western expansion of the United States. The river also became the subject of American literature, particularly in the writings of Mark Twain.

The Missouri River is a river in the Central and Mountain West regions of the United States. The nation's longest, it rises in the eastern Centennial Mountains of the Bitterroot Range of the Rocky Mountains of southwestern Montana, then flows east and south for 2,341 miles (3,767 km) before entering the Mississippi River north of St. Louis, Missouri. The river drains semi-arid watershed of more than 500,000 square miles (1,300,000 km), which includes parts of ten U.S. states and two Canadian provinces. Although a tributary of the Mississippi, the Missouri River is slightly longer and carries a comparable volume of water, though a fellow tributary (Ohio River) carries more water. When combined with the lower Mississippi River, it forms the world's fourth-longest river system.

For over 12,000 years, people have depended on the Missouri River and its tributaries as a source of sustenance and transportation. More than ten major groups of Native Americans populated the watershed, with most leading a nomadic lifestyle and dependent on enormous bison herds that roamed through the Great Plains. The first Europeans encountered the river in the late seventeenth century, and the region passed through Spanish and French hands before becoming part of the United States through the Louisiana Purchase.

The Illinois Country (French: Pays des Illinois [pɛ.i dez‿i.li.nwa]; lit. 'land of the Illinois people'; Spanish: País de los ilinueses), also referred to as Upper Louisiana (French: Haute-Louisiane [ot.lwi.zjan]; Spanish: Alta Luisiana), was a vast region of New France claimed in the 1600s that later fell under Spanish and British control before becoming what is now part of the Midwestern United States. While the area claimed included the entire Upper Mississippi River watershed, French colonial settlement was concentrated along the Mississippi and Illinois Rivers in what is now the U.S. states of Illinois and Missouri, with outposts on the Wabash River in Indiana. Explored in 1673 from Green Bay to the Arkansas River by the Canadien expedition of Louis Jolliet and Jacques Marquette, the area was claimed by France. It was settled primarily from the Pays d'en Haut in the context of the fur trade, and in the establishment of missions from Canada by French Catholic religious orders. Over time, the fur trade took some French to the far reaches of the Rocky Mountains, especially along the branches of the broad Missouri River valley. The "Illinois" in the territory's name is a reference to the Illinois Confederation, a group of related Algonquian native peoples.

The Illinois Country was governed from the French province of Canada until 1717 when, by order of King Louis XV, it was annexed to the French province of Louisiana, becoming known as "Upper Louisiana". By the mid-18th century, major settlements included Cahokia, Kaskaskia, Chartres, Saint Philippe, and Prairie du Rocher, all on the east side of the Mississippi in present-day Illinois; and Ste. Genevieve across the river in what is now Missouri, as well as Fort Vincennes in what is now Indiana.

An alpine lake is a high-altitude lake in a mountainous area, usually near or above the tree line, with extended periods of ice cover. These lakes are commonly glacial lakes formed from glacial activity (either current or in the past) but can also be formed from geological processes such as volcanic activity (volcanogenic lakes) or landslides (barrier lakes). Many alpine lakes that are fed from glacial meltwater have the characteristic bright turquoise green color as a result of glacial flour, suspended minerals derived from a glacier scouring the bedrock. When active glaciers are not supplying water to the lake, such as a majority of Rocky Mountains alpine lakes in the United States, the lakes may still be bright blue due to the lack of algal growth resulting from cold temperatures, lack of nutrient run-off from surrounding land, and lack of sediment input. The coloration and mountain locations of alpine lakes attract lots of recreational activity.

Alpine lakes are some of the most abundant types of lakes on Earth. In the Swiss Alps alone, there are nearly 1,000 alpine lakes, most of which formed after the Little Ice Age. As global temperatures continue to rise, more alpine lakes will be formed as glaciers recede and provide more run-off to surrounding areas, and existing lakes will see more biogeochemical changes and ecosystem shifts. An alpine lake's trophic state (i.e., level of biological productivity) progresses with age (e.g., low productivity after formation and increased productivity with vegetation and soil maturity in the surrounding watershed), but anthropogenic effects such as agriculture and climate change are rapidly affecting productivity levels in some lakes. These lakes are sensitive ecosystems and are particularly vulnerable to climate change due to the highly pronounced changes to ice and snow cover. Due to the importance of alpine lakes as sources of freshwater for agricultural and human use, the physical, chemical, and biological responses to climate change are being extensively studied.

The San Juan Mountains is a high and rugged mountain range in the Rocky Mountains in southwestern Colorado and northwestern New Mexico. The area is highly mineralized (the Colorado Mineral Belt) and figured in the gold and silver mining industry of early Colorado. Major towns, all old mining camps, include Creede, Lake City, Silverton, Ouray, and Telluride. Large scale mining has ended in the region, although independent prospectors still work claims throughout the range. The last large-scale mines were the Sunnyside Mine near Silverton, which operated until late in the 20th century, and the Idarado Mine on Red Mountain Pass, which closed in the 1970s. Famous old San Juan mines include the Camp Bird and Smuggler Union mines, both located between Telluride and Ouray.

The Summitville mine was the scene of a major environmental disaster in the 1990s when the liner of a cyanide-laced tailing pond began leaking heavily. Summitville is in the Summitville caldera, one of many extinct volcanoes making up the San Juan volcanic field. One, La Garita Caldera, is 35 miles (56 km) in diameter. Large beds of lava, some extending under the floor of the San Luis Valley, are characteristic of the eastern slope of the San Juans. The eruption of the La Garita Caldera shaped the San Juan Mountains by completely obliterating the volcanoes that once stood in the area.

Chihuahua, officially the Free and Sovereign State of Chihuahua, is one of the 31 states which, along with Mexico City, are the 32 federal entities of Mexico. It is located in the northwestern part of Mexico and is bordered by the states of Sonora to the west, Sinaloa to the southwest, Durango to the south, and Coahuila to the east. To the north and northeast, it shares an extensive border with the U.S. adjacent to the U.S. states of New Mexico and Texas. The state was named after its capital city, Chihuahua City; the largest city is Ciudad Juárez. In 1864 the city of Chihuahua was declared capital of Mexico by Benito Juárez during the Reform War and French intervention until 1867. The city of Parral was the largest producer of silver in the world in 1640. During the Mexican War of Independence, Miguel Hidalgo was executed on July 30, 1811, in Chihuahua city.

Although Chihuahua is primarily identified with its namesake, the Chihuahuan Desert, it has more forests than any other state in Mexico, aside from Durango. Due to its varied climate, the state has a large variety of fauna and flora. The state is mostly characterized by rugged mountainous terrain and wide river valleys. The Sierra Madre Occidental mountain range, part of the continental spine that also includes the Rocky Mountains, dominates the state's terrain, and is home to the state's greatest attraction, Las Barrancas del Cobre, or Copper Canyon, a canyon system larger and deeper than the Grand Canyon. The state also has the largest crystal cave in Mexico known as the Naica cave discovered in 2001. Chihuahua is also home to the archaeological site of Paquimé in Casas Grandes that was created by the people of the Mogollon culture of Northern Mexico and is recognized as an UNESCO World Heritage site. Chihuahua is the largest state in Mexico by area, with an area of 247,455 square kilometres (95,543 sq mi), it is slightly larger than the United Kingdom, and slightly smaller than Wyoming, the tenth largest US state by area. The state is consequently known under the nickname El Estado Grande ('The Great State' or 'The Big State').

Oregon Country was a large region of the Pacific Northwest of North America that was subject to a long dispute between the United Kingdom and the United States in the early 19th century. The area, which had been demarcated by the Treaty of 1818, consisted of the land north of 42° N latitude, south of 54°40′ N latitude, and west of the Rocky Mountains down to the Pacific Ocean and east to the Continental Divide. Article III of the 1818 treaty gave joint control to both nations for ten years, allowed land to be claimed, and guaranteed free navigation to all mercantile trade. However, both countries disputed the terms of the international treaty. Oregon Country was the American name, while the British used Columbia District for the region.

British and French Canadian fur traders had entered Oregon Country prior to 1810 before the arrival of American settlers from the mid-1830s onwards, which led to the foundation of the Provisional Government of Oregon. Its coastal areas north of the Columbia River were frequented by ships from all nations engaged in the maritime fur trade, with many vessels between the 1790s and 1810s coming from Boston. The Hudson's Bay Company, whose Columbia Department comprised most of the Oregon Country and north into New Caledonia and beyond 54°40′ N, with operations reaching tributaries of the Yukon River, managed and represented British interests in the region.

The Arkansas River is a major tributary of the Mississippi River. It generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's source basin lies in Colorado, specifically the Arkansas River Valley. The headwaters derive from the snowpack in the Sawatch and Mosquito mountain ranges. It flows east into Kansas and finally through Oklahoma and Arkansas, where it meets the Mississippi River.

At 1,469 miles (2,364 km), it is the sixth-longest river in the United States, the second-longest tributary in the Mississippi–Missouri system, and the 47th longest river in the world. Its origin is in the Rocky Mountains in Lake County, Colorado, near Leadville. In 1859, placer gold discovered in the Leadville area brought thousands seeking to strike it rich, but the easily recovered placer gold was quickly exhausted. The Arkansas River's mouth is at Napoleon, Arkansas, and its drainage basin covers nearly 170,000 square miles (440,000 km). Its volume is much smaller than the Missouri and Ohio rivers, with a mean discharge of about 40,000 cubic feet per second (1,100 m/s).

British Columbia is the westernmost province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, forests, lakes, mountains, inland deserts and grassy plains. British Columbia borders the province of Alberta to the east; the territories of Yukon and Northwest Territories to the north; the US states of Washington, Idaho and Montana to the south, and Alaska to the northwest. With an estimated population of over 5.7 million as of 2025, it is Canada's third-most populous province. The capital of British Columbia is Victoria, while the province's largest city is Vancouver. Vancouver and its suburbs together make up the third-largest metropolitan area in Canada, with the 2021 census recording 2.6 million people in Metro Vancouver. British Columbia is Canada's third-largest province in terms of total area, after Quebec and Ontario.

The first known human inhabitants of the area settled in British Columbia at least 10,000 years ago. Such groups include the Coast Salish, Tsilhqotʼin, and Haida peoples, among many others. One of the earliest British settlements in the area was Fort Victoria, established in 1843, which gave rise to the city of Victoria, the capital of the Colony of Vancouver Island. The Colony of British Columbia (1858–1866) was subsequently founded by Richard Clement Moody, and by the Royal Engineers, Columbia Detachment, in response to the Fraser Canyon Gold Rush. Moody selected the site for and founded the mainland colony's capital New Westminster. The colonies of Vancouver Island and British Columbia were incorporated in 1866, subsequent to which Victoria became the united colony's capital. In 1871, British Columbia entered Confederation as the sixth province of Canada, in enactment of the British Columbia Terms of Union.