California blue oaks range in height from shrubs to trees of ninety feet, with diameters of three or four feet. The average height is about forty-five and the diameter two or less. The trunk frequently divides a few feet from the ground into large limbs. That form excludes the wood from sawmills, and only in rare cases does any of it find its way there. The lumber is of poor quality, brittle, black, and otherwise defective. The sapwood is white and thick. A cubic foot weighs 55.64 pounds, or nearly ten more than eastern white oak. It is weak, and is low in elasticity. The annual rings are often nearly invisible, because the pores are scattered evenly and do not form bands. The medullary rays are broad, in the heart black, in the sapwood white. If the wood were otherwise suitable, pleasing effects might be produced by quarter-sawing, but as far as known, no attempts have been made to do this. Now and then a suitable log might be found. The importance of this oak lies in its fuel value. It rates above white oak in theoretical tests, but it is heavier in ash, and in practice it hardly measures up to white oak. It grows slowly and is destined to disappear as a source of fuel supply. Reproduction has nearly ceased in most parts of its range, due largely to the perseverance of hogs in eating the acorns. Cordwood cutters have stripped the last tree from large areas where much once grew. This oak never forms forests. The trees seldom grow as close together as apple trees in an orchard.
GAMBEL OAK (_Quercus gambelii_) was destined by nature to occupy an inferior place in the country’s timber resources. It occupies a region of stunted vegetation among the dry mountains and plateaus of the Southwest, and except where it grows in better situations than usual, it is too small to be properly called a tree. It is at its best among the mountains of southeastern Arizona where it grows in canyons that can maintain a little damp soil. There it occasionally reaches a height of thirty feet and a diameter of a foot or less. In most other parts of its range it is simply a tangled, sprawling thicket of brush, covering the dry, rocky mountain ridges, and along the bases of cliffs. It is found from Colorado to western Texas, and westward into Utah, Nevada, and Arizona. The leaves are small, thick, firm, and hairy, typical of desert foliage which must husband the scant water supply. The acorns are pretty large for a tree so stunted, and they are tempting bait for birds and rodents of the region. The acorns are sweet. If this oak’s reproduction depended on acorns alone it is doubtful if it would hold its ground in the face of perpetual adversity; but its roots send up distorted and stunted sprouts which cover the ground, affording hiding places for the few acorns which escape their hungry enemies. Man puts this oak to few uses. It affords a pretty good class of fuel for camp fires, but cordwood cutters cannot make much out of it. In rare instances frontier ranches use a few of the unshapely poles for corral fences, but only as a case of last resort. The names bestowed upon the tree by those who know it best are uncomplimentary. They call it shin oak, pin oak, scrub oak, mountain oak, and Rocky Mountain oak.