The mountain that moved: geologic wonders of the George Washington and Jefferson National Forests

Prehistoric, giant landslides in Montgomery and Craig Counties, Va., in the Blacksburg/Wythe Ranger Districts of the Jefferson National Forest, are the largest known landslides in eastern North America and are among the largest in the world. One of the landslides is more than 3 miles long! The ancient, giant landslides extend for more than 20 miles along the eastern slope of Sinking Creek Mountain. Enormous slabs of rock ranging from about 0.2 to more than 1.5 square miles in size broke loose and slid downslope under the influence of gravity. The movement of some slides may have been slow, but the movement of others was probably sudden and catastrophic.