Aspens and cottonwoods have chlorophyll in the bark and so can photosynthesize before produc-ing leaves. Lodgepole pine , the most obvious and abundant conifer in the park and parkway, grows on the lower slopes of the Tetons and on well-drained glacial soils throughout the valley. Large diameter trees have coarse, furrowed bark. Subalpine fir occurs on wetter north-facing valley sites and at higher elevations in the mountains. Smooth bark and spire-like growth form identify subalpine fir.
Needles occur singly and feel soft.
Cones grow upright on branches. Engelmann spruce occurs with subalpine fir, especially along creeks in the canyons between Teton peaks. Rough bark and abundant cones hanging down from upper branches identify Engelmann spruce. Blue spruce lines rivers and creeks in the valley. Cones have papery scales and are twice as large as those found on Engel-mann spruce.