
The Grand Canyon is probably the most famous geologic formation in the world. It is 216 miles long1,14–18 miles across, and about a mile deep. The first question most visitors express is, “How did this happen?” Many geologists have tried to answer this question and have proposed different theories as to how the canyon was formed.
- 1. The length, 216 miles, of the Grand Canyon should not be confused with the combined length, 277 miles, of the Grand Canyon and Marble Canyon. Both are located in Grand Canyon National Park.


Basaltic columns have been a mystery, not just for their
appearance of being ancient manmade structures, but for
the little known factors involved in their natural formation. 




