“I would tell anyone to take their vacation in Yellowstone this year,” William Romme told me. “This is a natural event not to be missed.” The natural event he was talking about is the multitude of fires that have burned about 650,000 acres so far in Yellowstone National Park. Romme is a professor of biology at Fort Lewis College in Durango, Colorado, and he has spent ten years–five of them on a National Science Foundation grant–putting together a fire history of a section of central Yellowstone Park. Working with National Park Service research biologist Don Despain and crews of student helpers, Romme walked the park’s backcountry, eventually surveying about 15 percent of Yellowstone’s 2.2 million acres.
So this summer’s fires, roughly 125 years after the last big ones, are about what we might expect in the last 25 years of the 20th century. This year, the driest year in memory, just happened to be the moment. Romme and Despain are cautious about giving reasons for the 100- to 150-year fire cycles. Dry weather is the likeliest cause.
Best of Chicago voting is live now. Vote for your favorites »
In the years since the National Park Service began keeping records of naturally occurring fires, an average of 17 fires per year–almost all caused by lightning–have been reported. That average includes swings from as few as 2 fires a year to as many as 50. In just the past ten years, Despain told me, the year-to-year differences in both the number and size of fires have been very great. He calls 1979 “a good fire year. We had some big fires–or what we thought of as big fires before this year.” In 1981, several fires burned about 20,000 acres. But from 1981 through August of 1987, a time when every natural fire was allowed to burn, not a single blaze covered as much as an acre. This year, when no rain fell for two months, the fires began to spread.
After World War II, smoke jumpers and aerial spraying of chemical extinguishers made fire suppression feasible. By 1972, the forests of Yellowstone averaged a little older than they would have been without the policy, but otherwise, things hadn’t changed much. The fires of the past 16 years have begun reestablishing the old balance.
Both Romme and Despain regard accurate mapping of the fires as a priority project for next spring. Wildfires are not all-consuming holocausts. They burn one hillside so hot that every living thing, plant or animal, not safely underground is incinerated. The 40-acre slope next door may be untouched. Unburned patches are refuges for wildlife and seed sources for the plants that will eventually recolonize the burned ground. When we learn the exact extent of the burned land, we will almost certainly discover that the fires actually consumed much less acreage than this summer’s news stories would suggest. Despain cites preliminary–and admittedly sketchy–reports, based on flights over the burned ground, of 30 to 50 percent destruction. In other words, of the 650,000 acres within the boundaries of the various fires, something between 195,000 and 325,000 acres were actually burned. This would represent from 9 to 15 percent of the park’s total area.
Change is slow in the cold, dry world of Yellowstone, where the growing season is short and blizzards can erupt in any month of the year. Lodgepole pine seeds will be germinating over the next five years–the nutrient-rich ash left by the fires is an ideal seedbed–but it will be 20 years before we notice the trees above the grasses, sedges, and wildflowers.
If you have been to Yellowstone, I’m sure you have memories of beautiful places and sublime sights, but I would argue that the most beautiful thing about Yellowstone is its size: 2.2 million acres, more than 3,400 square miles, an area equal to two-thirds of Connecticut. And the park is almost surrounded by national forests and Grand Teton National Park, where there are several million acres more of wilderness or near-wilderness lands.
