Yellowstone National Park - A Tapestry of Green

Northeastward, hazy in the distance, looms 10,243-foot Mount Washburn, the northern part of a 50-million-year-old volcano that lost much of its bulk in the collapse of the great Yellowstone Caldera. Despite that cataclysm, the summit is still almost 3,000 feet above the surrounding wilderness. It is only a few miles north of the center of the park, and the view from the top is panoramic, encompassing most of the park.

About five percent of Yellowstone is covered by water, most of which is in Yellowstone Lake. Another 80 percent is forested, and 80 percent is forested, and 80 percent of that is dominated by one kind of tree, the lodgepole pine. The lodgepoles do well here because they can survive on poor soil, and the rhyolite rock, born of the lava that filled the great caldera, breaks down into coarse, sandy soil that is poor indeed in many mineral nutrients. On hillsides, lakeshores, lower mountain slopes, and around the edges of meadows, the lodgepoles' slender, upright trunks, covered with thin, scalelike bark of brown or gray, crowd together, bearing their sparse crowns 50 feet or many above the forest floor.

In the clear mountain air the trees do not fade into distant haze as they seem to when viewed from lower elevations. Instead they gradually lose their individual identities, weaving themselves into a gently textured carpet. Stands of quaking aspens stipple the landscape, their soft green foliage creating a subtle, summer-long mosaic with the deeper tones of the conifers, a contrast that intensifies to high drama when the aspen leaves are touched with autumn color.

On higher slopes, perhaps beginning at about 8,000 feet, Englemann spruce and subalpine fir mix with the lodgepole pines. There is no strict cutoff, but as elevations increase, the rock of older volcanoes stands above the rhyolite, and it breaks down into richer soil. Hence, the yellowish-green lodgepole tapestry gradually incorporates the deep blue-greens of fir and spruce, until finally only the dark tones remain.

During the summer of 1988, drought and unprecedented winds caused intense fires in Yellowstone and surrounding areas. The face of the park changed drastically. Fortunately, vast sections of the dense forest survived, and losses to wildlife were surprisingly light. After the fire, regeneration began on a grand scale. Burned areas turned green, and meadows resrouted. In just a few years' time, most of Yellowstone will have attained a new splendor.