The margins are minutely toothed and stomatal lines occur on the surfaces. The apophyses are light yellowish-brown on young cones, becoming weathered and grayish on older trees. At maturity, prickles are absent from the umbos. Cones persist on the tree for several years, often remaining tightly closed. Adapted to survive forest fires in dry seasons, the cones slowly open at 140 degrees F, releasing the seeds slowly, allowing the ashes to cool before dissemination.
Buds are ovoid, resinous and dark brown, with blunt tips.
Bark on young trees is thin and reddish-brown to gray, becoming dark brown and scaly. On old trees the bark is divided into shallow furrows and scaly ridges of thick, close-pressed scales. This is the most northern pine and it is essentially a Canadian and Great Lakes species. It is native from near the Arctic Circle in Alaska south and east to the Great Lakes states and the northern New England states. The Jack pine is one of the hardiest native trees in North America, growing from zone 2 to 6.