This tree is also known as the golden cup oak because of the handsome acorns, one-half to one and one-half inches in length, which are characterized by scaly cups densely covered with bright yellow wool. The acorns mature at the end of the second year, and while a few are produced annually, large crops are common only at infrequent intervals.

Several additional features render it of particular interest. It is one of the evergreen broadleaved trees of the Park and the leaves, which are alternate on the branches and oblong in outline (about three inches long) persist for three or four years. They have a thick, leathery texture, are smooth and yellow-green above, and when young are covered with yellowish down on the underside. They vary considerably in size and appearance on trees of different age— in fact occasionally on parts of the same tree. Leaves of larger trees or older branches are generally smooth along the margin but young specimens, particularly vigorous shoots, bear foliage that has distinct spiny edges not unlike holly in appearance. This feature causes many park visitors to mistake young canyon live oaks for holly—a plant not found in the Yosemite region.

Mature specimens are generally from thirty to sixty feet tall with a short, heavy trunk two to three feet in diameter characterized by dark, flaky bark. Thick, heavy branches produce a wide spreading crown. However, this tree varies widely in size. In exposed locations at the upper altitudinal limits of its rangy it assumes a scrubby character.

The canyon live oak is found between the 3,000 and 6,000 foot elevations. It thrives in protected canyon bottoms, a fact responsible for its common name, and has a particular affinity for the talus slopes and rock slides bordering such places. It is one of the most abundant trees in those places about Yosemite Valley and will be readily found along the lower parts of trails leading from the Valley floor to the rim as in the case of the Yosemite Falls trail, the Four Mile Trail to Glaciar Point, about Happy Isles, and along the trail from that point to Nevada Fall.

It is a slow growing but fairly long lived tree. Mature specimens attain an age of from 200 to 300 years.