JACKSON - Wildlife may be having a hard time navigating through the web of roads in Yellowstone National Park, according to a Washington, D.C.-based group.

Public Employees for Environmental Responsibility has said it appears park officials are planning roadways based more like a Department of Motor Vehicles than a National Park Service.

"The planning is around road construction," said Jeff Ruch, PEER executive director. "They don't have kind of a comprehensive policy, even though it is by far the largest source of (wildlife) mortality."

Ruch said an employee of the park approached his group - which is an advocacy group for public employees - to complain about 24-hour gas stations in Yellowstone.

"That led to a larger, 'What was going on there?'" Ruch said. "To some extent, if you've got vehicle travel, you're likely to have accidents."

But Cheryl Matthews, spokeswoman for Yellowstone, said there are no filling stations open 24 hours, and most close at 7 p.m.

"I'm not sure where that came from," she said of the complaint.

From 1989 to 2003, an average of 103 large mammals have been killed each year due to vehicle collisions in Yellowstone. (A "large" mammal weighs more than 30 pounds, according to the Park Service.)

The peak of animal-car collisions was in 1994, when 148 animals were killed. The lowest number was in 2000, when there were 83 wildlife deaths.

The most common animal killed is elk, followed closely by mule deer. Bison is third, followed by coyotes and moose. There have also been beavers, whitetail deer and wolves killed by cars.

Ruch said he would like park officials to "devote some serious management attention to the causes of these problems."

"For example, do they want to discourage driving at dusk and dawn?" he said. "They may want to re-evaluate speed."

Ruch said Yellowstone is widening roadways, which may mean higher speeds and more wildlife killed.

He also said other parks have systems in place that alert drivers to wildlife on roadways.

Matthews said "much work" has been done examining speeds on roadways. Most of the park is a 45 mph speed limit.

And, she said, areas where road upgrades are occurring have a lower wildlife mortality rate because the construction improves visibility.

She said Yellowstone's roads were evaluated several years ago and given a lot of poor ratings for safety, hence the reconstruction projects.

"Road width and alignment enhances visitor access and safety," she said. "It helps wildlife because of sight distance and thinning of vegetation, and for through-traffic to negotiate through wildlife jams."

She said on the four segments of roads that have been upgraded, roadkills have dropped.

"Twenty-seven percent of park roads had 14 percent of park roadkill," she said. These upgrades have been on Craig Pass, at the east entrance, from Old Faithful to Madison and from Madison to Norris.

Matthews also said the park tried an experiment with crossing sensors that would alert motorists with flashing lights if wildlife stepped onto the roadway, but technical problems halted that effort.

This year, five black bears were hit and killed by cars, and one grizzly bear was hit and killed. That, Matthews said, is unusual, as the average between 1989 and 2003 is one black bear killed.

Biologists blamed the deaths earlier this year on a poor whitebark pine cone crop, which pushed bears down closer to people and to roadways in search of food as they tried to fatten up for the winter.

But Ruch said more research needs to focus on the effect of roads on wildlife.

"The way they treat roadkill, they treat it like the weather," he said. "It gets better or worse, and they don't know why, and there's nothing they can do about it."

Roadkill tally

Total animals killed on Yellowstone National Park roadways from 1989 to 2003:

* Antelope: 24

* Beaver: 17

* Bighorn sheep: 6

* Bison: 192

* Black bear: 12

* Bobcat: 3

* Coyote: 135

* Elk: 566

* Grizzly bear: 5

* Moose: 112

* Mountain lion: 2

* Mule deer: 456

* Raccoon: 8

* Whitetail deer: 10

* Wolf: 11

Source: National Park Service

Environmental reporter Whitney Royster can be reached at (307) 734-0260 or at royster@trib.com.