The Biggest Impact Crater in Alabama is the Length of 69 Football Fields!

Written by Drew Wood
Updated: June 8, 2023
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Yes, believe it or not, the biggest impact crater in Alabama is 4.7 miles in diameter! This is the length of 69 football fields! The Wetumpka impact crater is located just east of Wetumpka, a city of over 7,000 just north of Montgomery. In this article, we’ll discover details about this amazing crater. We’ll also cover what Alabama was like then, and what the effects would be if it happened again. Buckle up and join us as we explore what must have been the worst day in Alabama’s history!

Key Points

  • The biggest impact crater in Alabama is at Wetumpka, just north of Montgomery.
  • It measures 4.7 miles in diameter and was the result of a meteor explosion 85 million years ago.
  • The object that hit the Earth was about 1,100 feet in diameter.
  • The explosion was likely as big as 1/3 of all the world’s nuclear weapons combined.
  • Southern Alabama, at the time, was an ocean. Sea creatures like plesiosaurs and mosasaurs resided there.
  • An asteroid of this size could strike the planet again, and NASA is tracking a possible candidate.
  • New technologies may enable us to deflect or reposition asteroids for our protection or economic advantage.
  • The odds of death by a meteor strike are fantastically small. This issue is more of a long-term threat to the human race than anything of concern in modern times.
Alabama - US State, River, Flowing, Gulf Coast States, Horizontal

The Coosa River in Wetumpka is near the site of the biggest impact crater in Alabama.


Hidden in Plain Sight

The Moon is peppered with impact craters. Though they formed many years ago, they are still visible today. This is because there is no weather and little geologic activity to erode them away. Logically, the Earth itself, traveling with the Moon through the cosmos, has had just as many impacts. But our craters have been worn down by weather, filled in by volcanic lava flows, and covered with vegetation. So, craters are quite a bit trickier to discover on Earth.

Researchers doing geologic mapping in Alabama suspected there was an impact crater at Wetumpka as early as the 1960s. But they couldn’t prove it until the 1990s when researchers found shocked quartz in a core sample. It’s now internationally recognized as a genuine impact site. It’s well-preserved, but it’s deeply buried and covered in vegetation and is mainly on private land. Simply put, you’re not likely to see a whole lot if you go driving around the area looking for it.

Janssen (lunar crater)

Earth likely has been impacted by just as many meteors as the Moon during its long history.

©NASA (image by Lunar Reconnaissance Orbiter) / public domain – License

What Caused the Biggest Impact Crater in Alabama?

From studying the site, including the geologic layers and fossils at the bottom of the crater, researchers believe it to be the result of a meteor impact that happened approximately 85 million years ago in the late Cretaceous period. The object that caused it would have been about 1,100 feet in diameter and struck from the northeast, impacting a sea that was 300-400 feet deep. It left behind a crater 4.7 miles in diameter. The force of the impact could have been as great as 1,000 megatons of TNT, which is about 1/3 the size of every nuclear weapon on Earth today, combined! The devastation such an impact would cause would be continent-wide.

Nuclear Explosion

The explosion that created the Wetumpka Crater would have been the equivalent of 1/3 of the power of every nuclear weapon in the world today.

©Romolo Tavani/

What Lived in Alabama at the Time of Impact?

The Cretaceous Period dates from 145 to 66 million years ago, which is the end of the Age of the Dinosaurs. Southern Alabama was an ocean at this time, about 85 million years ago. Fossils from that time show a lot of sea creatures that are pretty much the same as we have today, like snails, clams, crabs, sea urchins, sharks, and rays. But there were also some very interesting extinct reptiles roaming Alabama’s seas as well.


The plesiosaurus was not technically classified as a dinosaur, but a prehistoric marine reptile that had a long neck, small head, wide body, a short tail, and two pairs of limbs sticking out the side of its body like paddles. This is the creature the infamous Loch Ness Monster legend was based upon.


The plesiosaurus was one of the large prehistoric reptiles swimming the sea over southern Alabama 85 million years ago.

©Lefteris Papaulakis/


The mosasaurus was another kind of aquatic prehistoric reptile. It was similar to a whale and at about 56 feet long, it was larger than a tyrannosaurus rex! Like whales, they breathed air, gave birth to live young, and spent most of their time near the surface of the water. Researchers have found several mosasaurus teeth in the geologic layers of Alabama’s Cretaceous sea.


The mosasaurus was a large carnivorous whale-like prehistoric reptile.

©Esteban De Armas/

Could It Happen Again?

Scarily enough, it could happen again. There is actually an asteroid named Apophis that is estimated to be about 1,210 feet in diameter – a little bigger than the Wetumpka meteor. It orbits the Sun in a little less than a year and makes a close pass of the Earth every couple of decades. Astronomers say we won’t have to fear an impact within the next century or so, but beyond that, it’s hard to say.

Governments around the world are working on improving the means of detecting and tracking objects in space. NASA even successfully conducted a mission to change the orbit of a small asteroid by crashing a rocket into it. This technology could be used one day not only to protect our planet from catastrophic impacts but also to reposition asteroids with valuable minerals in safe Earth orbits to make it easier to develop them commercially.

An asteroid is about to hit the Moon

Developing technologies may enable us to deflect asteroids from dangerous paths or even deliberately position them in safe Earth orbits.

©Marti Bug Catcher/

What Are the Chances?

So, what are the chances that you or I will actually die from a meteor collision? Fortunately, very small. About 70% of the Earth is water. Of the land surface, at least 50% is pretty much unpopulated, such as ice sheets, deserts, mountains, and other areas that are not hospitable to people. This means that if an asteroid is going to hit a random spot on the planet, there’s an 85% chance it will be someplace where no one lives.

The odds of dying at the hands of a meteor are about 1 in 250,000. Any of us has a much higher chance of crashing in a plane (1 in 30,000). If you’ve been pinning your retirement hopes on the lottery, there’s bad news for you though. The chances of winning the PowerBall are about 1 in 195,000,000. With those odds, you’re more likely to be hit by multiple meteors in your lifetime! Considering how very unlikely it is that a meteor would hit the same place twice, maybe Wetumpka is the most meteor-proof place in the country!

Where is Wetumpka Located on a Map?

Wetumpka, a municipality in Elmore County, Alabama, serves as the county seat, with a population of 7,220 according to the 2020 census. Elmore County has experienced rapid growth in the early 21st century, emerging as one of the fastest-growing counties in the state. Wetumpka is also included within the Montgomery Metropolitan Area.

Here is Wetumpka on a map:

The photo featured at the top of this post is © Triff/

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About the Author

Drew Wood is a writer at A-Z Animals focusing on mammals, geography, and world cultures. Drew has worked in research and writing for over 20 years and holds a Masters in Foreign Affairs (1992) and a Doctorate in Religion (2009). A resident of Nebraska, Drew enjoys Brazilian jiu-jitsu, movies, and being an emotional support human to four dogs.

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