Habitat
Widespread in the foothills & lower mountain elevations. 5,500-8,000 ft. After a fire, Gambel oak quickly re-establishes itself from root sprouts. Associated plant species include chokecherry, arrowleaf balsamroot, bigtooth maple, mountain-mahogany, ponderosa pine, and serviceberry.

Flowers
Inconspicuous flowers (unisexual catkins) occur in the spring.

Description
Easily recognized because of the unique lobed leaves. Small deciduous tree or large shrub. Usually 10' to 30' tall but can grow taller.

Leave are very distinctive, generally 3" - 5" long & deeply lobed on each side of the central vein. The upper surface of the leaves is glossy dark green; the undersurface is paler and velvety. Leaves frequently turn orange and yellow during autumn, creating mountainsides of vivid colors.
Reproduces from acorns but spreads most rapidly from root sprouts that grow from vast underground structures called lignotubers. These reproductive characteristics often result in dense groves or thickets of the trees that often cover entire mountainsides. Acorns are about 3/4" long and about 1/3 to 1/2 covered by the capsule. Acorns mature in September, turning from green to golden brown.
Branches are irregular and crooked, making them flexible enough to bend without breaking. The bark of the tree is a rough brownish-gray.

Comments
Historically, acorns from Gambel oak provided a reliable source of food for Native Americans.

Source: Wikipedia