The tree has a height from sixty to a hundred feet; sometimes it attains a diameter of three and one-half feet. It carries a broad and compact crown, especially when the tree is surrounded by young coniferous growth as is the case in its best habitat where natural pruning gets rid of the lower limbs and causes an outward and later a pendulous growth of the upper part. The limbs are strong and heavy as are the branches and twigs. The bark is a grayish-brown with shallow fissures, the broad ridges being sometimes broken across forming square plates which are covered with the grayish flakes or scales. The buds are long and acute, and are coated with a red fuzz. The leaves are from four to six inches long and are bilaterally developed, having seven or nine coarse round lobes; the sinuses being rounded or rather shallow. The color is a dark lustrous green and the texture leathery. The acorn is rather large being about an inch and a quarter in length and usually about half as broad as long; has a shallow cup covered with pointed sometimes elongated scales. This oak is one of the most important hardwoods of the far Northwest. It is often compared with the eastern white oak, but its physical properties fall below that species in some important particulars. The two woods weigh about the same, but the eastern species is stronger and more elastic, and is of better color and figure. All oaks season somewhat slowly, but the Pacific post oak is hardly up to the average. It is a common saying that it must remain two years on the sticks to fit it for the shop, but that time may be shortened in many instances. Checking must be carefully guarded against. Some of this oak is exceedingly tough, and when carefully sorted and prepared it is excellent material for heavy wagons; but the best comes from young and comparatively small trees. When they attain large size they are apt to become brash. The tree usually grows rapidly, and is not old in proportion to the size of its trunk. An examination of the wood shows broad bands of summerwood and narrow, very porous springwood. The medullary rays are broad and numerous, and ought to show well in quarter-sawed stock; but it does not appear that much quarter-sawing has been done. Practically all of this species cut in the United States is credited to Oregon in the census of sawmill output in 1910. The cut was 2,887,000 feet, and was produced by fourteen sawmills, while in Washington only one mill reported any oak, and the quantity was only 4,000 feet. On the northwest Pacific coast it comes in competition with eastern oak and also with Siberian or Japanese oak.