Wyoming wildlife faces twin threats

Drill rigs and houses gobble habitat and sever migration routes

  • Antelope pass by a subdivision near Pinedale, Wyoming

    Noah Brenner

PINEDALE, Wyoming — Every spring and fall, a herd of pronghorn passes through a series of hay meadows on the western edge of town. The antelope are migrating between the Wind River Mountains and winter range in the sagebrush of the Upper Green River Valley.

But over the last 13 years, construction of a home-furnishings store, a pizza joint, and a state Department of Transportation barn has narrowed that migration route from at least a mile wide to 240 feet wide — earning those meadows the nickname "Antelope Alley." And in the last six months, construction crews have begun to build a motel and roads and houses for a half-dozen new subdivisions on the remaining open ground.

The developers promise to limit fencing and dogs. But Wyoming Game and Fish Department Regional Supervisor Bernie Holz expects that the herd of 300 to 1,000 pronghorn will quit using Antelope Alley. "They’re a high-strung animal," sensitive to human presence, he says. "They’ll be very reluctant to pass through that area." Over time, he adds, the herd may find another route skirting the town.

It’s ironic: Major newspapers from The New York Times to the Los Angeles Times have reported a different problem around here. Their headlines warn that the area’s spectacular wildlife community — which includes tens of thousands of pronghorn and deer, and one of the West’s largest populations of sage grouse — is threatened by a spectacular rush to extract natural gas.

Huge corporations, including EnCana and Shell, draw more than a billion cubic feet of gas per day from more than 3,000 wells in the area, and they plan to triple the number of wells within 15 years. The energy development fragments wildlife habitat and may sever some of the dozens of migration routes that thread from the mountains to the valley floor (HCN, 8/18/03: Where the Antelope and the Oil Companies Play).

But that’s only half the story.

Fastest-growing county in two respects

The gas rush targets several hundred thousand acres so far, mostly sagebrush in the valley managed by the federal Bureau of Land Management. But the energy development has been tempered by opposition from conservation groups, including the Upper Green River Valley Coalition. As a result, the BLM and the energy companies are taking steps to leave room for wildlife.

In November, the BLM gave permission for one company, Questar, to expand its drilling in critical winter range for deer, even though an ongoing study shows that deer are driven away by drilling activity. But Questar is paying for the deer study, and limiting the amount of land it disturbs by using more directional drilling, in which several wells are drilled from each pad. Questar is also building pipelines that will reduce truck traffic. Other companies are using directional drilling and working to limit air pollution from diesel engines.

In September, Democratic Gov. Dave Freudenthal and Republican Sen. Craig Thomas helped persuade the Bridger-Teton National Forest to pull back from leasing 157,000 acres for gas drilling (HCN, 9/27/04: Energy companies rush the West).

Some locals believe that residential development poses at least as much of a threat as the energy boom. Pinedale is the biggest town in Sublette County, which still feels rural; about 6,400 people are scattered over its 3 million acres. However, Sublette is growing faster than any other Wyoming county; the population has soared 30 percent since 1990. Gas-field workers are pouring in, along with affluent people from California and other states, attracted by the grand scenery, recreation and small-town lifestyle.

The Pinedale city and Sublette County governments approved more than 200 new lots within a mile of town last year alone. Ranches are being broken up into two- to 10-acre ranchettes. An American Farmland Trust study in 2002 ranked Sublette County tops in Wyoming in the amount of ranch land threatened by development. By 2020, 336,000 acres of ranch land may be converted to residential use. Nonetheless, officials in Sublette County have been reluctant to do anything to slow the rapid development of private land.

Property rights rule

Local officials view restrictions on subdivisions as an infringement of private-property rights. They also say the new subdivisions are needed to provide more affordable housing, as an antidote to soaring real estate prices.

"We have that issue (impacts on wildlife) rear its ugly head every time we talk about building in Sublette County," said County Commissioner Betty Fear in May, voting for an Antelope Alley subdivision. "We have to look at habitat for humans as well."

The county government struggled to create a Purchase of Development Rights program, which would use oil and gas taxes to pay ranchers not to subdivide. But the first major purchase has been stalled by a lawsuit, pressed by a retired engineer and the Mountain States Legal Foundation, a Denver-based property-rights law firm.

The Green River Valley Land Trust, formed in 2000, has helped ranchers put conservation easements on about 10,000 acres, but progress is slow. In general, rural homesteads and subdivisions reduce the populations of native birds and mammals, says Andy Hansen, a Montana State University ecology professor. Such impacts can last "hundreds of years," he says.

Biologists are still trying to determine how antelope and deer will react to both the real estate boom and the gas rush. "The gas fields fall on critical winter range. Most of the subdivisions currently are falling along the migration pathways," says Joel Berger, a Wildlife Conservation Society biologist. "So it’s a double whammy."

Noah Brenner writes from Pinedale. Ray Ring, HCN’s editor in the field, contributed to this story.


Upper Green River Valley Coalition in Pinedale, www.uppergreen.org, 307-367-3670

Green River Valley Land Trust in Pinedale, www.grvlandtrust.org, 307-367-7007

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