The mountains ranges in North America have both young and old mountains.The young Rocky Mountains are the longest mountain range in North America. They are considered young as they show no sign of erosion. Also in the west, the Sierra Nevada and Cascade are young mountains as well. The Cascade ranges are part of the Pacific Ring of Fire and have many active volcanoes. The young Alaskan Range is the tallest of the mountain ranges in North America. The Appalachian Mountains on the eastern side, on the other hand, are considered to be much older, and their peaks have been eroded through the ages and are flatter.
The Icy Alaskan mountains
The St. Elias Mountain Range also lies in Alaska, and runs along the border between Canada and USA on the northwestern side of the continent. The Wrangell is also part of the St. Elias Range. St. Elias is home to many glaciers and has some of the most extensive icy fields in the world, extending for 380 kilometers (235 miles), and are second only to the polar regions. Mount Logan, and then St. Elias, are the highest peaks in this mountain range. Mount Logan is the highest peak in Canada, and the second highest in North America.
The tallest mountain in North America is Mount McKinley, or Denali, and is the third tallest of the First Summits in the world. Denali, an original Koyukon native name meaning "the high one", has been reinstated as its name officially since 2015. Besides the controversy about its name, it is also well known as an important adventure destination in North America. Climbing expeditions to Mount Denali are made difficult by the weather and its steep vertical slopes. Being at 630N latitude, Denali also has lower air pressure than other high mountain ranges. Only an estimated 32,000 have attempted the climb, and only half have succeeded in reaching the peak. The difficulty can be judged by the fact that there have been more than 100 deaths during expeditions. Though four exploration or expeditions were made since the late eighteenth century, it was Hudson Stuck, Walter Harper, Harry Karston and Robert Tatum who were the first to reach the peak in 1913.
Ecological significance of the mountains
Mountains in general are an essential part of the hydrological cycle on earth. On their icy peaks, precipitation comes down as snow and is stored until summer melts the snow to form rivers, providing water to the mountains and plains below. The floodplains of these rivers are highly productive and very important also for natural ecosystems. Many aquatic, terrestrial and avian species depend on them for survival and movement.
In North America, people source 85% of their water from the mountain rivers for agriculture and hydroelectric power generation. Spreading human settlements and activity have altered the structure and flow of these rivers, which are also essential to natural wild populations. These floodplains are now some of the most threatened habitats in the world. Moreover, these mountains are more sensitive to climate change than plains, and the high peaks have experienced three times the global rise in temperature in the last century. Changes in wind, solar radiation, snow depth, and snow cover influence avalanches and wildfire events, change glacier mass, and affect alpine vegetation. Changes in snow mass and temperature influence water flow in floodplains as well. As a result climate change increases stress to these habitats, further endangering many species' survival.
The Highest Summits Of The United States
|Rank||Mountain Peak||Mountain Range||State||Elevation (in feet)|
|1||Denali (Mount Mc. Kinley)||Alaska Range||Alaska||20,310|
|2||Mount Saint Elias||Saint Elias Mountains||Alaska||18,009|
|3||Mount Foraker||Alaska Range||Alaska||17,400|
|4||Mount Bona||Saint Elias Mountains||Alaska||16,550|
|5||Mount Blackburn||Wrangell Mountains||Alaska||16,390|
|6||Mount Sanford||Wrangell Mountains||Alaska||16,237|
|7||Mount Fair-weather||Saint Elias Mountains||Alaska||15,325|
|8||Mount Hubbard||Saint Elias Mountains||Alaska||14,951|
|9||Mount Bear||Saint Elias Mountains||Alaska||14,831|
|10||Mount Hunter||Alaska Range||Alaska||14,573|