WILLISTON, N.D. – A critter crossing large enough to accommodate moose will go under an expanded U.S. Highway 85 near Williston, helping wildlife travel through habitat that’s now divided by heavy oilfield traffic.

Future wildlife crossings, including overpasses for bighorn sheep and pronghorn antelope, are being studied for other critical habitat areas in North Dakota’s Oil Patch.

The North Dakota Game and Fish Department relocated a herd of bighorn sheep last year by helicopter to reduce road-kill incidents along Highway 85. Recently, the department researched wildlife crossings in Montana and other states to find solutions as traffic counts in western North Dakota are projected to keep increasing.

“We’ve never really had the concentrated traffic like we’re seeing here, especially the large traffic and pretty much 24/7,” said Bruce Kreft, conservation biologist with the department.

The four-laning of Highway 85 between Williston and Watford City, which includes replacing the Lewis & Clark Bridge that crosses the Missouri River, provided an opportunity to incorporate a wildlife crossing, Kreft said.

The project will involve constructing a 40-foot-wide by 15-foot-tall underpass to allow animals to safely cross about a quarter-mile south of the bridge, which is a natural wildlife travel corridor. It will also include fencing along the highway and “jump-outs,” or one-way exits to prevent animals getting stuck.

The Game and Fish Department estimates that 100 moose are thriving along the Missouri River bottoms just south of Williston, along with white-tailed deer and other animals.

“There’s a lot of very unique species coming across this area,” Kreft said.

The daily traffic count on that bridge, which was 2,425 vehicles per day in 2006, had an estimated 13,245 vehicles per day in 2012, according to the North Dakota Department of Transportation. The vehicle count, which includes a large percentage of heavy trucks, is projected to be 22,000 vehicles per day in the future.

Kent Luttschwager, wildlife resource management supervisor for the North Dakota Game and Fish Department, estimates that at least six moose have been killed in vehicle crashes in the past couple of years. Statistics from the Department of Transportation are incomplete, he said, because motorists are not required to report all wildlife-vehicle crashes.

Hitting a moose poses a greater risk to the motorist because the animal often comes through the windshield in a crash, Luttschwager said.

“It can be deadly to certainly the moose and also the motorist,” said Luttschwager, who counted a vehicle passing about every two seconds last week in the area where the crossing will be.

The state has had nine human fatalities resulting from wildlife-vehicle collisions since 2001, Kreft said.

The estimated cost of the wildlife crossing, along with other mitigation and conservation measures that are planned for the project, is about $2.6 million. The highway project is required to have some mitigation measures because it will affect a designated Wildlife Management Area, Luttschwager said.

The Game and Fish Department plans to monitor the crossing using remote cameras. Research from other states shows that animals need to learn to use the crossings, and it may take time before they are accustomed to using it, Kreft said.

The wildlife crossing will be the first of its kind for North Dakota, said Jamie Olson, spokeswoman for the North Dakota Department of Transportation.

The road portion of the four-lane Highway 85 project from Alexander to Williston will go out for bids in July and is tentatively expected to be complete by fall 2015, Olson said. The bridge portion of the project will take longer and is anticipated to be complete in 2016, she said.

The Game and Fish Department also has identified other areas for potential wildlife crossings on Highway 85, including crossings near the North Unit of Theodore Roosevelt National Park and Grassy Butte for bighorn sheep, pronghorn antelope and mule deer, Kreft said.

Research shows that pronghorn antelope will not use an underpass or a tunnel, Kreft said. Another type of crossing that has been used in other areas is a fenced overpass that is seeded with grass, he said.

“We know we’re experiencing mortality,” Kreft said of the traffic impacts on wildlife. “There is something that can help. It’s not a solution, but it’s a step in the right direction.”

listen live watch live