The leaf appears to have more space than leaf surface. The BARK is smooth and gray on smaller trees and becomes rough and broken with age. It commonly reproduces through stump sprouts , therefore often grows in clumps. It can be very difficult to tell the difference between poor quality red oak and normal pin oak. Deep sinuses generally cut nearly to the mid-vein of most leaves.
Acorns usually grow at the end of a short stalk.
Terminal BUDS are oval, sometimes with short hairs. The thick, medium-gray BARK allows the tree to survive most ground fires, which is why bur oak is sometimes called prairie oak. It was one of the few trees to survive the frequent prairie fires. It probably was not a component of the U.P. forest until European settlement. Sinus depth variable.