Ranked: The Oldest Mountain Ranges in the United States

Appalachian Trail, Hiking, Virginia - US State, Blue Ridge Mountains, Blue
© iStock.com/Wilsilver77

Written by Kristen Holder

Updated: September 26, 2023

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A mountain is an area of land that rises from the earth’s crust by at least 1000 feet. The famous and towering mountain ranges in the western United States, the Rocky Mountains, and the Sierra Nevada, are geological infants compared to the country’s oldest mountains. We have compiled details and ranked the oldest mountain ranges in the United States by age. Let’s take a look now. 

Ranked #6: Black Hills at 70 Million Years Old

Black Hills

The Black Hills is a solitary mountain range in South Dakota and Wyoming.


The Black Hills is a solitary mountain range in South Dakota and Wyoming. The highest peak is over 7,000 feet in elevation, though peaks were up to 15,000 feet tall millions of years ago. Humans have lived there for over 10,000 years, and white settlers flooded the area in a gold rush during the 19th century.

An uplift occurred around the Cretaceous and Paleogene boundary, which created these hills. The core of these hills is made of rock that was created over two billion years ago.

The Lakota name for the mountains is Paha Sapa, meaning “black hills.” This refers to the black silhouettes of the mountains on the horizon when looking at the mountains from a distance.

The Black Hills spruce is an endemic tree. Wildlife includes American bison, bighorn sheep, prairie dogs, northern flying squirrels, and ruffed grouse. The white-winged junco is endemic to the area.

Mount Rushmore is a famous tourist stop in the region. The faces of presidents Abraham Lincoln, Theodore Roosevelt, Thomas Jefferson, and George Washington are carved into the rock of Mount Rushmore.

Ranked #5: Arbuckle Mountains at 300 Million Years Old

The Arbuckle Mountains

The Arbuckle Mountains lie between the Rocky Mountains and the Appalachians.


Between the Rocky Mountains and the Appalachians lies the Arbuckle Mountains in Oklahoma. They are the oldest geological development located between these two major ranges.

The core of this mountain range consists of materials that came into being over 1.4 billion years ago. The top layer was created over 290 million years ago as sediment from a now-extinct ocean built up over time.

There is an important aquifer beneath these mountains called the Arbuckle-Simpson aquifer. Water seepage through thick limestone has created a cave network. The area has fault lines, including the North Sulphur and South Sulphur faults.

The highest peak is a little over 1,400 feet above sea level, though this looks truncated as the surrounding land is also elevated. This is why they’re sometimes called hills, even though they’re technically tiny mountains.

They were much larger in the past, but they’ve eroded over time. This erosion makes these mountains more of a plateau with lots of ridges.

Ranked #4: Ouachita Mountains at 300 Million Years Old

Ouachita Mountains

The name Ouachita refers back to the original indigenous people of the region.

©Tammo2011 / CC0 1.0 – Original / License

Located in southeast Oklahoma, the Ouachita Mountains are the leftovers of a much larger mountain range that no longer exists. This larger extinct range probably extended from Canada to Texas. The Ozark Plateaus and the Ouachitas make up the U.S. Interior Highlands.

There is a noticeable endemic flora population. Some local plants include Ouachita bluet, Browne’s waterleaf, Arkansas gayfeather, Ouachita Mountain goldenrod, narrow-leaf ironweed, and Palmer’s cornsalad.

The name Ouachita refers back to the original indigenous people of the region. When the French colonialists found these mountains, they Latinized the indigenous word into what it is today.

Ranked #3: Presidential Range at 350 Million Years Old

Mount Washington, New Hampshire

Mount Washington is in the Presidential Range.

©iStock.com/Gerald G Gantar

Most of the Appalachian Mountains are temperate, though a few exceptions exist. One is Mount Washington in the Presidential Range, and that and surrounding peaks provide over 7.5 square miles of the area above the timberline.

Mount Washington sometimes experiences winds above 200 miles per hour. It’s also freezing and has never been over 71 degrees Fahrenheit since modern record-keeping began.

The Presidential Range is part of the White Mountains, and the White Mountains occupy a large swath of New Hampshire and a bit of Maine. The range is known for being rugged and has some of the most difficult terrain encountered on the Appalachian Trail.

Ranked #2: Appalachian Mountains at 480 Million Years Old

Beautiful autumn mountains scenery. Appalachian mountains in autumn colors. Grandfather Mountain State Park. Banner Elk, North Carolina, USA

The Appalachian Mountains are a mountain range in the eastern United States and Canada.


The Appalachian Mountains are a mountain range in the eastern United States and Canada. These mountains extend from Alabama to Newfoundland.

They came into existence around 100 million years before terrestrial animals evolved. They also existed before the Atlantic Ocean.

Furthermore, they’re decreasing in size because the tectonics that created them are no longer near them. They were once very tall, but erosion has reduced their height.

This mountain range has three major sections: southern, central, and northern. The Appalachians are the rough divide between the eastern United States and the Midwest. The Blue Ridge Mountains are one of the oldest parts of the Appalachians and may be over a billion years old.

There are various animals found at different spots in these mountains. Some notable creatures are black bears, spring peepers, eastern copperheads, timber rattlesnakes, North American cougars, and eastern wolves.

In the spring, wildflowers draw tourists to the Appalachians. By April, flowers like laurels, azaleas, and rhododendrons begin blooming in the south of the range. This trend sweeps upward as spring progresses.

Because of the isolation of some highlands in the Appalachian Mountains, a distinct culture developed. Folklore and music are examples of the kind of unique developments that took place in these mountain communities.

Ranked #1: Uwharrie Mountains at 500 Million Years Old

Uwharrie Mountain range in north carolina

The Uwharrie Mountains were originally 20,000 feet tall.


Located in North Carolina, these mountains are so old that their tallest peak is only 1,100 feet. Originally, they were 20,000 feet tall. They were also originally on the coast and are now 150 miles inland.

Historically, these mountains were completely cleared for farming and wood harvesting. In 1961, President Kennedy designated this range as a national forest, and native plant life is again present.

The North Carolina Zoo is in the Uwharrie region and is one of two state-supported zoos in the USA. It was the first of the two state-sponsored zoos in the United States to be established.

What is the Oldest Mountain Range on the Earth?

The last sun of the afternoon, illuminating a ridge covered in Aloes in the Baberton-Makhonjwa mountains

It is hard to believe that the Barberton Makhonjwa Mountains have been standing for 3.5 billion years!

©Marieke Peche/iStock via Getty Images

The Barberton Makhonjwa Mountains of South Africa and into the Kingdom of Eswatini are the oldest mountain range on Earth. At an estimated age of 3.5 billion years, these majestic mountains are some of the most ancient landscapes on the entire planet.

The Barberton Makhonjwa Mountains are home to a wide variety of unique flora and fauna, many of which are found nowhere else in the world. These mountains are home to blue wildebeests, red hartebeests, impalas, elephants, caracals, and jackals! The unique geology and topography of the mountains also create a unique environment, making them a popular destination for hikers, climbers, and researchers.

Summary of the Oldest Mountain Ranges in the United States

RankMountain RangeAge
1Uwharrie Mountains500 Million Years
2Appalachian Mountains480 Million Years
3Presidential Range350 Million Years
4Ouachita Mountains300 Million Years
5Arbuckle Mountains300 Million Years

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About the Author

Kristen Holder is a writer at A-Z Animals primarily covering topics related to history, travel, pets, and obscure scientific issues. Kristen has been writing professionally for 3 years, and she holds a Bachelor's Degree from the University of California, Riverside, which she obtained in 2009. After living in California, Washington, and Arizona, she is now a permanent resident of Iowa. Kristen loves to dote on her 3 cats, and she spends her free time coming up with adventures that allow her to explore her new home.

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