Established in 1872, Yellowstone National Park is the oldest, largest (in the lower 48 states), and best-known national park. Its 890,000 hectares sprawl across broad volcanic plateaus that soar some 2,450 meters above sea level. Three states, Wyoming, Montana and Idaho, lay claim to Yellowstone's beauty. Enclosed by the Grand Teton National Park to the south and a half dozen national forests, the Yellowstone region shelters a tremendous expanse of unbroken forest, lush grassland, dramatic mountain ranges, spectacular valleys, deep lakes, and winding river canyons. It is a geological wonderland of fossil forests, hot springs, mud cauldrons, painted pots, and geysers. Its diverse wildlife community includes bear, elk, bison, coyotes, trumpeter swans, bald eagles, beaver, trout, and a host of smaller and microscopic creatures. Small wonder, then, that millions of people from all over the world visit the park every year. The visitor services and the science research centers at Yellowstone are among the best in the world. Yellowstone National Park is an international treasure. So sensitive and under such intense scrutiny are the eco-systems of Yellowstone that if a tree falls in the Yellowstone forest, the odds are quite good it will be heard not only across the U.S. but around much of the world.

Lodgepole Pine is King
When you drive through Yellowstone, you'll pass lovely paintbrush flowers, sand verbena, Rocky Mountain juniper bushes, fields of grassland, patches of aspen trees, and several species of spruce and fir trees. But by far and away the most common tree you'll see, covering some 80 percent of Yellowstone's forests, is the lodgepole pine. It grows straight and tall and up to 23 meters high. In forests where the pines are dense, only the tops of the trees closest to sunlight have branches, and you get the sensation you have entered a forest of thousands upon thousands of telephone poles topped with Christmas trees.

How did the lodgepole pine become so common in Yellowstone? Curiously enough, the reason has to do with the periodic wildfires that sweep through these forests. After a fire strikes, while other tree species must wait for the right conditions or for some spare seeds to drift in from a neighboring forest, the eager-beaver lodgepole is prepared, having on hand two types of cones that are custom-made for fires. Adult lodgepoles produce both open cones and serotinous cones.

Open cones shed their seeds in the normal way when the cones reach maturity. Serotinous cones, on the other hand, have a resin coating, and they only open when temperatures are 45º C. or higher, which, in the relatively cool climate of Yellowstone, happens only in the heat of a fire. As soon as the ground cools off, lodgepole seeds from the serotinous cones germinate. The seedlings spring from the ash-enriched soils. These trees also grow rapidly, maturing (that is, producing their own dual-type cones) as early as five years after sprouting.