This is the first in a series called “Ancient Alabama,” examining the natural forces that made Alabama what it is over the past 500 million years, and how those forces still shape the state today.
Every year, thousands of people visit Alabama’s Cheaha State Park to see the tallest peak in the state, climb the steps of the observation tower built on the summit and take in the view stretching miles and miles in each direction.
It’s easy to see why Cheaha was Alabama’s first state park, why the Civilian Conservation Corps built that observation tower in 1933, and why so many people today make the drive about 30 minutes south of Anniston to see the peak and climb the tower.
But I prefer the second highest point in the state. It’s a perch on a giant boulder about 100 yards away from the actual peak at Cheaha. By my untrained eye, it looks to be almost as high as the real summit, which is 2,407 feet above sea level, but it’s more isolated. You don’t have to line up to climb the steps of the tower or wait for the woman up top urging someone on the ground to take her picture.
When the Appalachian Mountains were being thrust up around 299 million years ago, they likely reached higher than Mt. Everest is today.Graphics by Ramsey Archibald
You won’t get the panoramic views of east Alabama you would from the tower or from the park’s Pulpit Rock or Bald Rock, but if you face away from the tower and the road leading up to it, you can almost forget that you’re in a state park with paved roads and sort of decent cell phone service.
You can just sit on the cool, hard sandstone that’s been there for millions of years, watch the trees that have been growing up around the boulders, and the birds and butterflies that flit in and out of them. It’s quiet enough to hear the autumn leaves drop from the trees and rustle all the way down to the floor below.
The birds and squirrels and insects that scattered at your arrival begin to reemerge and show the depth of the forest’s wildlife tapestry. You can begin to imagine what it might have been like before there was a tower or a state park or asphalt or cell phones.
A lot of people don’t think of Alabama as a mountain state. That may be because they’ve never been to Cheaha or Lookout Mountain. It also could be because they’re too focused on the present.
Look back a couple hundred million years, and Alabama had some of the tallest mountains in the world, likely taller than any on Earth today.
Solving an ancient mystery
Figuring out how high mountains used to be hundreds of millions of years ago is sort of like piecing together a crime scene from long before humans walked the Earth. All mountains on Earth will eventually erode down to nothing if given enough time, leaving little indication that they were ever there.
A sign at Cheaha State Park boasts that the mountain range that included Cheaha was once twice as high as Mt. Everest is now. That’s higher than most estimates of how tall those mountains used to be, but there’s a lot of uncertainty.
Jim Lacefield, a retired professor and author of the book “Lost Worlds in Alabama Rocks,” said it’s impossible to estimate how high Alabama’s mountains once were with a high degree of accuracy, so he stayed away from comparisons to specific peaks like Everest.
Overlook at Cheaha State ParkDennis Pillion
He does refer to those mountains though as “Alabama’s Lost Himalayas,” saying the mountains could have at least rivaled today’s highest peaks.
When trying to learn about mountains that are long gone or have already eroded significantly, geologists look for clues in the way the rock layers are slanted in the dirt and what kinds of metamorphic rocks are at the base.
The slant of the rock layers can provide clues about how much force was generated when the continents collided and where the tallest peaks would have been.
The mountains that remain today are barely shadows of what was there previously. There’s a prime example of that in DeKalb County, according to Lacefield, where Lookout and Sand Mountain face each other across a lush valley.
If you drive down Alabama Highway 35 from Rainsville toward Fort Payne, you can see layers of rock where construction crews cut into Sand Mountain to build the road. Those layers show the old sedimentary rock built up in flat layers for millions of years before being pushed up into mountains.
If you keep going a few miles southeast down into Will’s Valley and across Big Wills Creek, you’ll see the same kind of rock layers where the roads go up Lookout Mountain.
What you probably won’t notice, but geologists like Lacefield did, is that those rock layers are near-perfect mirror images of each other. So perfect, in fact, that they show that once upon a time, Lookout Mountain and Sand Mountain were not two separate peaks at all, but two sides of the same mountain, which wind and water have worn down over millions of years.
“These counter-matching rock layers exposed on either side show that this valley was not formed by simple erosion cutting into a flat plain, but instead cutting down into broad, arching fold in the Earth’s crust,” Lacefield writes. “What must once have been a huge, folded mountain has been transformed by erosion over time into the scenic valley that exists here today.”
The African collision
What forces could create such massive peaks? Just the African continent, moving fast to crash into the rest of the Earth’s landmasses to create Pangea, the supercontinent.
Lacefield says you can think of mountains being formed in the same way dirt is piled up by a bulldozer’s blade.
Going back 500 million years, Alabama was mostly underwater and well south of the Equator, slowly drifting north toward the tropics. That went on for 200 million years or so, when these drifting continents began to bump into each other.
The various land masses had basically consolidated into two large continents: one called Laurasia, containing what’s now Europe, North America and part of Asia, and the other, Gondwana with Africa, South America. Then, about 323 million years ago, Gondwana barreled into Laurasia, thrusting up all those mountains, and creating the supercontinent Pangea.
The continent didn’t stop on a dime, but kept pushing and grinding northward for millions of years, piling up mountains as it went. In Alabama, Lacefield said the mountain-building event likely peaked around 299 million years ago, pushing the mountains to their highest points, whatever they might have been.
Observation tower built at Mt. Cheaha in 1933 by the Civilian Conservation Corps.Dennis Pillion
Alabama’s ‘lost’ desert years
After the collision, Alabama went from being almost completely underwater to being thrust up above the sea and surrounded by land on all sides. Now landlocked and dry, Alabama was basically a desert. And we don’t know a whole lot else about it.
Lacefield says there’s a more than 200-million-year gap in the state’s geologic record from this time, with no rocks found here formed during that time. Most of the rocks we have in Alabama were formed from marine sediments, meaning they were created when runoff from the land flowed into the ocean and hardened into rock.
With Alabama now far from the nearest ocean, those sediments were carried elsewhere and didn’t leave any records here. That would continue until Pangea broke apart and Alabama got a coastline again, during the age of the dinosaurs.
That’s a story we’ll pick up in the next installment of Ancient Alabama, when we meet the Appalachiosaurus, an evolutionary cousin to the famed Tyrannosaurus Rex and the apex predator of Alabama’s tropical jungles about 80 million years ago.
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