Because Yellowstone is a national park, it’s possible to think of it as one place nature is safe.
And it’s true that the park’s 2.2 million acres have never been the site of any mining or lumbering. Its absence of mineral wealth, in fact, is a big reason we have the park at all: When it was created, in the 1870s, the industrial revolution was in high gear, exploiting every resource in site. But Yellowstone’s corner of Wyoming just didn’t seem to have anything the robber barons wanted just then. (Trees we could get anywhere.)
Yet Yellowstone isn’t safe. And that’s not just because of invasive species like the lake trout, introduced intentionally by the U.S. Army when it ran the park, which have forced the native cutthroat trout into a fraction of their original habitat. Or the New Zealand mud snail, introduced by accident, that’s pretty much wiped out all other aquatic life in some portions of Yellowstone.
Yellowstone’s troubles, inf act, go beyond even the threat of climate change, which could irreversibly alter the habitat, rendering it unlivable for some plant and animal species.
A harder to recognize threat to Yellowstone is that it’s just not big enough. Despite its vastness, it’s only one part of a bigger ecosystem — a larger network of waterways, forests, meadows and other habitats that most of its animals need to remain unbroken and unpolluted to survive.
Author and professional mountain guide Jack Turner gives this ecosystem a name in his terrific and curmudgeonly 2008 book Travels in the Greater Yellowstone (Thomas Dunne Books), which I started reading while I was visiting the park this past summer.
Turner defines Greater Yellowstone as an 18-million acre swath of Idaho, Montana and Wyoming, of which Yellowstone National Park is only about 12 percent. But the protection of Greater Yellowstone is vital to the survival of Yellowstone for many reasons.
Many of Yellowstone’s rivers originate outside the park; if they’re polluted by mining or agricultural runoff, so is Yellowstone, where neither of those activities take place. Likewise the paving or other building upon land that elk, say, migrate through; breaking up continuous terrain will harm those animals. Likewise creatures like grizzly, which don’t migrate but range over very wide areas to forage for food.
As Turner points out, the park is hemmed in on all sides by land that people want for their own purposes: farms, mines, roads, ranches, subdivisions. Too much of them, and the park will be poisoned. Too much of them, and the creatures we associate with the park won’t survive.
And yet not even laws against pavement and mines and farms can alone save Yellowstone.
The park is at high altitude, most of it with cool temperatures even in summer, a fact that much of its plant and animal life depend on. Not to mention its snowpack. (Western rivers get most of their flow from snowpack, he notes.)
Turner’s most haunting image might be his suggestion that climate change is creating a thermal sea around the park. As it rises, it covers the lowlands and surrounds the peaks. That turns what was once continuous habitat into a series of islands, none of them big enough to support species who need more range.
Yellowstone — far from safe — is just another canary in our ecological coal mine.