Rocky Mountains – A Great North American Range

The Rocky Mountain Range is made up of a set of discontinuous mountain ranges that have a distinctive geological history.

The core of the Rocky Mountains were formed over a billion years ago through colliding tectonic plates and the uplift of the continental crust.

The Rocky Mountains were shaped during a period of high tectonic plate activity, the last of which being during the Laramide orogeny approximately 80-55 million years ago. The rugged shape of the Rocky Mountains we see today is also the result of subsequent glacial erosion.

Different sections of the range have more distinctive formations due to the way the tectonic plates shifted in those areas. In the northern sections of the Rockies in Canada, the collision of the plates pushed and bunched up the mountains. 

An unusual subduction shaped the Rocky Mountains in the U.S. This was a result of the Farallon Plate being subducted under the North American Plate at a shallow angle, which resulted in more friction and piled layers of crust on top of one another.

Topography

The Rocky Mountains are an extensive range of mountains that span all the way from Northern British Columbia in Canada to New Mexico in the United States of America (see: hikes in New Mexico). The range forms part of the enormous mountain system that is the Northern American Cordillera.

Some of the highest peaks in North America are found in the Rocky Mountains, including Mount Elbert (4,401m) and Mount Harvard (4,395m).

While there are numerous mountain towns located in the Rocky Mountains, the human population is quite sparse. There is an average density of 4 people per square km.

Climate

In a very general sense, the climate of the Rocky Mountains is considered to be a highland climate with wet, cold winters and warm, dry summers with thunderstorms. However, because the range extends for such a long distance and spans through different regions, its climate varies throughout its different sections.

The Canadian Rockies have more extreme and unpredictable weather conditions. Temperatures are dependent on elevation, dropping approximately 5˚C per 1,000 meters of elevation gained.

The winter months are very cold with temperatures frequently dropping to about -22˚ F (-30˚C) and there is steady snowfall from November to March. Summer is from June to August with July being the hottest month as temperatures reach 86˚F (30˚C).

As the Rocky Mountains move further south into the United States, the climate becomes drier with less rainfall. Thunderstorms are common occurrences during the summer months from June to August. Spring has very unpredictable weather where it can sporadically change from hot to cold or wet to dry. The average winter and summer temperatures are 28˚F (-2˚C) and 59˚F (15˚C) respectively.

Wildlife and Plants

The vegetation in the Rocky Mountains varies between its different regions, elevations and exposure. Therefore, the Rockies can be divided into several biotic zones, which are characterized based on whether they can support tree life and whether there are any indicator species present in the zone.

There are two biotic zones in the Rocky Mountains that do not support trees: the Alpine tundra and the Plains. The Great Plains lie on the eastern side of the mountains and consist mostly of prairie grasses at low elevations. Scattered cedar and pine trees can be found on the eastern slopes but their growth is generally stunted and warped by the strong winter winds.

The Alpine tundra zone lies at higher elevations above the tree line on the mountains. Trees do not grow in this zone due to the high elevations and harsher conditions.

The Rocky Mountains have ten different forest zones. Junipers, pines and oaks can be found in the southern regions where the climate is warmer and drier, while Douglas firs, aspens, spruce and Cascadian species can be found in the colder, wetter climate of the northern sections of the mountain range. Unique forest zones can also be found around the rivers and canyons in the drier regions of the Rockies.

There is abundant wildlife in the Rocky Mountains. The range supports a number of well-known animals, such as elk, white-tailed deer, moose, mountain goat, mule and bighorn sheep. Numerous predators can be found in the Rockies including black and grizzly bears, coyotes, wolverines and lynxes.