Where Do the Rocky Mountains Start and End?

Written by Colby Maxwell
Updated: August 21, 2022
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The Rocky Mountains are some of the most distinctive mountain ranges in the United States. This expansive range is beautiful, huge, and one of the defining features of all land west of the Mississippi. Despite their simple name, the Rockies are actually some of the largest mountains in the world. Let’s explore a bit more about this wonderful range and where the Rocky Mountains start and end.

Where do the Rocky Mountains start and end?

Where Do the Rocky Mountains Start and End?

Beginning in the far north of Canada and ending in New Mexico, the Rocky Mountains measure 3,000 miles long.


The Rocky Mountains start in the northernmost part of western Canada and end in New Mexico in the southwestern United States.

When people think of North American mountain ranges, two usually come to mind; the Appalachian Mountains and the Rockies. Although the two are both well known, the Rockies are significantly larger, taller, and longer than the Appalachians.

The total length of the Rockies measures 3,000 miles in a straight line, with the average width of the range measuring 400 miles. In the north, otherwise known as its northern terminus, is somewhere south of the Liard River and the Brooks Range, close to the Alaska/Yukon border. The southern terminus is located near the Albuquerque region, close to the Rio Grande Basin.

The Rockies are a part of a large group of related mountains known as the North American Cordillera. The North American Cordillera includes most of the large ranges in the western portion of North America, including the Rockies, the Sierra Nevadas, the Cascades, all of the Alaskan ranges, and many more.

How long have the Rocky Mountains been around?

Where Do the Rocky Mountains Start and End?

The Rockies formed around 50-80 million years ago.

©Pat Tr/Shutterstock.com

As a general rule, the taller and sharper a range is, the newer it is. Ranges that have been around for a long time are eroded and rounded (like the Appalachians). The modern-day Rockies formed around 50 to 80 million years ago during a geologic period known as the Laramide orogeny.

Like many of the other ranges in the world, the Rockies were formed when tectonic plates collided, pushing the surface of the earth upwards, forming mountain ranges. The Rockies were formed when a few plates began to slide under the large North American plate, causing the range to push up from the earth.

Although the range has been around for longer than the human species has, humans have been living in the range for quite some time. The first people to inhabit the range entered during the end of the last ice age, as the land bridge from Russia to Alaska was likely still present.

How tall are the Rocky Mountains?

Where Do the Rocky Mountains Start and End?

Denali is the tallest mountain in all of North America.


The Rocky Mountains are among the tallest mountain ranges in the United States. There are three major ranges in the US, including the Rockies, the Appalachians, and the Sierra Nevadas. Of the three, the Rockies are the longest by quite a bit. In fact, the Rockies are the second-longest mountain range in the entire world. The tallest (non-major) mountain range in the United States is the Alaska Range, home to Denali, the tallest mountain in North America.

The highest point in the Rockies is listed as 14,440 feet and is located on Mount Elbert in Colorado. Mount Massive (14,428 feet) and Mount Harvard (14,421 feet) hold the second and third highest peaks in the range, respectively. Each of the three tallest peaks is located within a smaller “subrange” within the Rockies known as the Sawatch Range. Additionally, all three of the peaks are found within Colorado, the state with 78 of the tallest 100 peaks in the country.

In another article, you can find out the length of the Rocky Mountains.

What are the largest mountain ranges in the world?

Where Do the Rocky Mountains Start and End?

Mount Everest is the tallest mountain in the world.


Although the Rockies are large, they aren’t at the top in height or length. The tallest mountain range in the world is the Himilayan Mountains. The famous peak of the Himalayas is Mount Everest, measuring 29,031.7 feet, nearly double that of the tallest peaks of the lower 48. The only peak in the United States that comes close is Denali, otherwise known as Mount McKinley, measuring 20,310 feet.

The longest mountain range in the world is only a short trip to the south of the Rockies. Located along the western coast of South America, the Andes is the longest mountain range in the entire world. From top to bottom, the Andes measure 5,500 miles in total. Additionally, the Andes are the second-tallest range in the world (with the Himalayas being number one).

What is the oldest mountain range in the world?

The Rockies are the second-longest range in the world. But on a geological scale, they aren’t all that old. Despite their 50 to 80 million years, the Rockies are actually among the newest ranges in the world. Currently, the oldest mountain range in the world is the Makhonjwa Mountains in South Africa, with some rocks dating to around 3.6 billion years ago. Although some rocks in Greenland and Canada can be dated to 4 billion years ago, they aren’t currently a part of a mountain range.

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The photo featured at the top of this post is © iStock.com/nick1803

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About the Author

Colby is a writer at A-Z Animals primarily covering outdoors, unique animal stories, and science news. Colby has been writing about science news and animals for five years and holds a bachelor's degree from SEU. A resident of NYC, you can find him camping, exploring, and telling everyone about what birds he saw at his local birdfeeder.

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