See Where Asteroids Impacted Missouri Millions of Years Ago
There is one place in Missouri that bears a scar from a collision with a space rock millions of years ago. It's a crater from a mighty impact from an asteroid that struck the land around 300 million years ago.
The United States Meteorite Impact Craters website has a fascinating story about the Decaturville Impact Crater in Missouri. If you look at it from a satellite, you can barely see the hint of a circular impact.
This site was first discovered back in 1873 and was originally thought to be an ancient volcano because of the rock found there. It wasn't until the 1960's and 1970's that scientists began to make the argument that this area was hit by a meteorite. They say they finally had evidence of "unambiguous confirmation of impacts required diagnostic indicators of shock metamorphism." Translation? The land there was shaped by a sudden impact.
That's not the only place in Missouri with geography changed by meteorites. There's also what's known as the Weaubleau impact structure in west-central Missouri southeast of Kansas City.
Crater Explorer shows that there are THREE impact locations in Missouri that have all been confirmed.
Since I'm not a geology major (wasn't covered in 2nd grade), I'll defer to this Missouri professor who breaks down the 3 Missouri meteor impact locations better than I can.
It's incredible to imagine what these impacts must have been like in that ancient era in Missouri. The rocks left behind and the shapes of the land in those areas only begin to hint about what that must have been like.