The chestnut oak tree, also known as rock oak or mountain oak, is a member of the white oak group of trees. Native to the Eastern US, this tree is medium-sized, slow growing, and deciduous. It can grow to a height of 60 to 70 feet, with trunks 3 to 4 feet in diameter. The chestnut oak can grow in mountainous areas and rocky habitats and is considered a ridge top tree on the Eastern seaboard.
The bark of the chestnut oak is very dark gray or brown, ridged, and rough, and is one of the tree's distinguishing characteristics. It contains more tannins than other oaks and was once highly prized in the tanning industry. On older trees, the bark grows in long ridges separated by deep furrows. The wood of the tree is used primarily for firewood and construction. However, the branches grow low and are not always straight, making it a sometimes less than favorable tree for timber.
When the tree is around 20 years old, it will start to develop acorns. These are large and a popular source of food for many types of wildlife. The chestnut oak can live for a long time. The famous Washington Oak, that grew in New York on the banks of the Hudson River, was estimated to be about 800 to 1000 years old.
Leaves on the chestnut oak are green with medium green undersides. In the fall, they turn chartreuse to yellow brown and the tree is bare by late autumn. The compound leaves grow to be 4 to 9 inches long with rounded or sharp teeth along their edges. Ten to fifteen leaves form on each cluster.