The forests of these three states are richly varied. They are forests of different colors--the gray bark of Douglas-fir, cinnamon-orange bark of ponderosa pine, white bark of aspen, and dark-colored bark of black spruce. Conifers such as fir, spruce, and pine have needles in different shades of green or blue-green. Larch needles and aspen leaves turn bright gold in the fall.

Forests have trees of different ages and sizes. Some tree seeds are small enough to hold several on your fingertip. The largest Douglas-fir ever found weighed about 175 tons and was nearly 300 feet tall when it died, and it grew from one of those tiny seeds.

Over the past 75 years, scientists at the Pacific Northwest Research Station have learned much about the forests of Alaska, Oregon, and Washington.

Douglas-Fir Forest - Old mature stage

Ponderosa Pine Forest - Old mature stage

Areas in Oregon and Washington with at least 25-percent tree canopy cover.