Now, the best way to determine a tree's age is to examine its rings, which is usually done with a screw-like device known as a borer that carefully extracts a small rod-shaped core from the tree. Currey decided that this tree in particular seemed like an asshole, though, so he and a park ranger just cut the tree down to count the rings more easily.
University of Arizona
Sawing a tree down is a lot less boring.
Once the rings were visible, Currey realized that the tree he'd just killed was more than 5,000 years old. That made it the oldest living organism in recorded history at the time. When that tree first sprouted, mammoths still walked the Earth.
Years later, we actually did find an older tree, but this should in no way take away from the fact that Donald Currey really cored the pooch on this one.