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