Thanks, Chad. You made me look. The New Madrid is close, but according to this it was the Wilzetta Fault, which is also known as the Seminole Uplift.

It was an unreal feeling.

http://en.wikipedia.org/wiki/2011_Oklahoma_earthquake

Quote:

There is a long ignored fault line there. That once caused enormous earth quakes.
http://en.wikipedia.org/wiki/New_Madrid_Seismic_Zone