PORTLAND - Geologists think Mount Hood is sitting on shakey ground.
The Oregonian first reported that scientists have discovered a previously undetected - and active fault zone on the mountain.
Scientists said the faults could also prove dangerous.
The fault zone stretches about 20 miles from the northern flank of Mt. Hood to the Columbia River.
Hidden by trees and dense vegetation, it had gone unnoticed.
State scientists discovered the fault line using aircraft equipped with LIDAR - a high-tech laser scanning mapping system.
Oregon State Department of Geology Chief Scientist Ian Mayden helped map out the faults and believes they likely make up one massive fault that at one point in history ruptured, causing the earth to break apart some six feet.
Teams began preparing to dig a big trench in the next few weeks across the faults to try and determine when the last earthquake occured.