The extreme edge of the Eastern hemlock's southern range is the Appalachians. However, over 200 of these trees thrive in the Hemlock Bluffs Nature Preserve in Cary. Scientists believe this group of trees are naturally occurring remnants of the last glacial age. Discovered in 1971, the area is approximately three acres in size, and the temperature in the bluff area is about ten degrees lower than surrounding areas, a perfect temperature for hemlocks to grow. The preserve is now classified as a State Nature and Historic Preserve.