Engelmann spruce is a long-lived, native, coniferous, evergreen tree. It is one of the largest of the high-elevation mountain conifers.
Mature trees have a narrow, pyramid form and short, compact branches.
Dead lower limbs tend to be persistent. The crowns of open-grown trees often extend down to the ground. In alpine areas just above treeline, Engelmann spruce often forms a krummholz. The young twigs are finely pubescent, a characteristic which differentiates this spruce from white spruce, which has glabrous twigs. The bark is very thin, grayish-brown on young trees but at maturity becomes purplish brown to russet and is broken into loosely attached scales.