The Appalachian Mountains occupy a towering spot in North American cultural identity. For many, the iconic mountain range calls to mind the extensive Appalachian Trail or the distinct dialect of Appalachian English, but the rugged peaks have been influencing the continent—and the world—for a lot longer than we’ve been around to appreciate them.
Here are 11 things you might not know about the Appalachian Mountains.

1. Some of the oldest parts of the Appalachian Mountains are more than 1 billion years old.

The Appalachian Mountains have been a fixture of the North American landscape for a long while, but exactly how old they are is a complicated question. Partly, that’s due to the fact that the range didn’t form all at once. Mountains in the Appalachian region have cropped up several times—only to erode back down again.

The first mountains that appeared might have done so as long as a billion years ago [PDF], when North America and South America merged together as part of a supercontinent. After those mountains wore away, another set emerged about 450 million years ago, and the cycle continued. Though today’s topography of the Appalachian Mountains dates to about 20 million years, as West Virginia University geology professor Steve Kite told West Virginia Public Broadcasting, some areas are made up of rocks that are a whopping 1.2 billion years old.

2. The Appalachian Mountains are nearly 2000 miles long.

While you may think of “Appalachia” as a region of the southern United States, the full Appalachian Mountains have a massive (not to mention international!) footprint. At their northern tip, they rise in Newfoundland and Labrador, Canada. From there, they wind south, all the way to central Alabama. All told, the range cuts through 18 American states and five Canadian provinces.

3. The Southern Appalachian Mountains formed when two continents collided.

Three hundred million years ago, the landmass that would become North America collided with something called Gondwana, a supercontinent made up of today’s Africa and South America. The result of the crash pushed Gondwana northward on top of North America, over which it slid for as far as roughly 186 miles (300 kilometers). A short 100 million years later, the two continents finally separated again, leaving the southern base of the Appalachians behind as a souvenir. Researchers at Brown University who studied the formation say the process probably looked a whole lot like the rise of the Himalayas.

4. The Appalachian Mountains could once have been as tall as the Himalayas.

The Appalachian Mountains may not be tall, but that doesn't make them any less wondrous.carlosalvarez/Getty Images

Since the original Appalachians formed long before humans could measure them—and before humans were around, period—we’ll never know for sure how high they were at their peak (pun intended). But scientists believe the Appalachian Mountains were much taller long ago than they are now.

Today, the Appalachians are at their highest in North Carolina, rising a measly 6684 feet. (In comparison, the Rocky Mountains boast more than 50 peaks that reach above 14,000 feet.). But evidence suggests it wasn’t always this way. In fact, geologists think the Appalachians may once have stood as tall as Asia’s Himalayas, which just so happen to include Mount Everest’s roughly 29,000-foot summit.

5. The Appalachian Mountains may have contributed to an Ice Age.

As we know all too well, high levels of carbon dioxide in the atmosphere lead to a rise in global temperature. So it’s surprising that the huge number of volcanic eruptions that helped form some of the northern Appalachian Mountains 460 million years ago—and spewed the most CO2 the world had ever seen while they were at it—didn’t lead to long-term high temperatures. More surprising still is that scientists believe the eruptions may actually have done the opposite. A mere 15 million years after the eruptions, the earth plunged into an ice age.

Research conducted by geologist Seth Young, of Indiana University, Bloomington, suggests that the reason for this surprising turn of events lies in the mountain rocks themselves. As acid rain from the carbon-dense air hit the Appalachians, it created limestone that ultimately eroded into the now-disappeared Nevada sea, sequestering the carbon and driving the global temperature down—then down some more.

6. The Appalachian Mountains played a role in westward expansion.

Long before Europeans arrived on the continent, Native American and First Nations tribes lived in the Appalachian Mountains. And for years after the colonists showed up, it stayed that way. The newcomers, on the other hand, remained on the eastern side of the range, having little incentive to brave the trek up and over into lands that belonged to somebody else. But after the Seven Years’ War (also known as the French and Indian War), the British Empire acquired huge swaths of what is now the U.S. and Canada, claiming for itself everything east of the Mississippi.

In an attempt to stop land-hungry settlers from traveling over the mountains—which the government across the pond knew would lead to conflict with the many tribes currently living there—the British crown issued the Royal Proclamation of 1763. The law officially forbade the colonists from settling anywhere past the Appalachian Mountains. Like many of the ordinances coming from London at the time, however, this one did little more than stoke resentment in the colonies—particularly among the elites who would soon lead the American Revolution.

7. The Appalachian Mountains form a continental divide.

The size of the Appalachian Mountains has an impact on more than just human movement. As the tallest points around, the Appalachian Mountains form a line that cleaves the eastern landscape of North America. The Eastern Continental Divide (or sometimes, the Appalachian Divide) marks the split that determines where rainfall in the region ends up. When precipitation drains down the east side of the mountains, it eventually finds its way to the Atlantic Ocean. Water that flows down the western side of the peaks, on the other hand, ultimately feeds into the Gulf of Mexico.

8. More than 3 million people hike the Appalachian Trail every year.

Thru-hikers follow these white blazes from Georgia to Maine.kellyvandellen/iStock via Getty Images Plus

The Appalachian Trail is one of the most iconic hiking trails in the world. Due to its length and stunning scenery, people have flocked there since the trail’s completion in 1937.

While 3 million people hike some part of the trail each year, a much smaller set of 3000 adventurous types attempt to trek the entire thing. Getting from start to finish in a single year (called a “thru-hike”) is no easy feat, and only about 10 to 15 percent of people who start out make it all the way. It’s not hard to see why: Thru-hikers must traverse 2193 miles across 14 states, not to mention managing the approximate 464,500 feet of elevation gain/loss along the way. That’s a lot of trail mix.

9. The Appalachian Mountains house some of the most biodiverse ecosystems in North America.

With such a massive geographical footprint, it’s no surprise that the wide range of Appalachian Mountain landscapes are home to a wide range of flora and fauna. Giant broad-leaf deciduous forests host 140 species of trees, and sweeping grasslands are peppered with wildflowers. (Hikers can find plenty of ferns, mosses, and mushrooms, too!)

Many of North America’s most celebrated wildlife also call the mountains home. The area is favored by elk, caribou, moose, and white-tailed deer, as well as black bears, foxes, and wild boars. And that’s just what’s on land. More than 250 species of birds, including falcons, eagles, and songbirds, soar overhead.

10. The Appalachian Mountains are made of some of North America’s most famous mountain ranges.

While the “Appalachians” is a blanket term that describes the full system of mountains, many well-known mountain ranges (technically “subranges”) can be found within them. Some of the most famous include the Blue Ridge Mountains (which span multiple southern states), the Great Smoky Mountains (the childhood home of Dolly Parton), and Massachusetts’s Berkshires.

11. Coal mining has destroyed some Appalachian Mountain peaks.

The Appalachian mountains include some of the most plentiful coal reserves in the world, and Americans have long taken notice. In the 19th and early 20th centuries, miners reached these lucrative deposits by drilling into the mountains, but things have since taken quite a turn. In the 1990s, mining companies debuted the much more efficient (and destructive) strategy of blowing the tops off mountains to get at the valuable resources within. In the process, forests were destroyed, streams were polluted, and iconic mountain silhouettes were no more. New guidelines introduced in 2010 by the Environmental Protection Agency aimed to reduce the damage, and advocacy groups have pressured multiple companies to agree to cease the practice.