Geography - note:
note 1: world's third-largest country by size (after Russia and Canada) and by population (after China and India); Denali (Mt. McKinley) is the highest point (6,190 m) in North America and Death Valley the lowest point (-86 m) on the continent
note 2: the western coast of the United States and southern coast of Alaska lie along the Ring of Fire, a belt of active volcanoes and earthquake epicenters bordering the Pacific Ocean; up to 90% of the world's earthquakes and some 75% of the world's volcanoes occur within the Ring of Fire
note 3: the Aleutian Islands are a chain of volcanic islands that divide the Bering Sea (north) from the main Pacific Ocean (south); they extend about 1,800 km westward from the Alaskan Peninsula; the archipelago consists of 14 larger islands, 55 smaller islands, and hundreds of islets; there are 41 active volcanoes on the islands, which together form a large northern section of the Ring of Fire
note 4: Mammoth Cave, in west-central Kentucky, is the world's longest known cave system with more than 650 km (405 miles) of surveyed passageways, which is nearly twice as long as the second-longest cave system, the Sac Actun underwater cave in Mexico - the world's longest underwater cave system (see "Geography - note" under Mexico);
note 5: Kazumura Cave on the island of Hawaii is the world's longest and deepest lava tube cave; it has been surveyed at 66 km (41 mi) long and 1,102 m (3,614 ft) deep
note 6: Bracken Cave outside of San Antonio, Texas is the world's largest bat cave; it is the summer home to the largest colony of bats in the world; an estimated 20 million Mexican free-tailed bats roost in the cave from March to October making it the world's largest known concentration of mammals
note 7: the US is reliant on foreign imports for 100% of its needs for the following strategic resources - Arsenic, Cesium, Fluorspar, Gallium, Graphite, Indium, Manganese, Niobium, Rare Earths, Rubidium, Scandium, Tantalum, Yttrium; see Appendix H: Strategic Materials for further details
note 8: three food crops are generally acknowledged to be native to areas of what is now the United States: cranberries, pecans, and sunflowers
Definition: This entry includes miscellaneous geographic information of significance not included elsewhere.
Source: CIA World Factbook - This page was last updated on Saturday, September 18, 2021
