HUSON — Interstate highways fragment wildlife habitat and hinder, if not completely stop, important animal migration, but an effort is afoot to reduce those problems on Interstate 90 west of Missoula.
On Wednesday night, more than 30 residents of the Ninemile area gathered in the Nine Mile Community Center to hear members of the Missoula Regional Connectivity Group describe a potential highway project that would allow wildlife to pass below Interstate 90 between Huson and Alberton and why the location was ideal.
“If you drive along I-90 leaving the Ninemile going toward Missoula, you go over Cayuse Hill. It’s the divide between Sixmile and Ninemile, and there are four crosses there. That shows there were four fatalities, and I was told a couple were due to hitting wildlife. Maybe all of them were, because there’s a ton of wildlife there,” said Pat Sweeney of the Ninemile Wildlife Working Group. “This project will help to maybe alleviate that.”
The Missoula Regional Connectivity Group is a loose collaboration of individuals, about a dozen organizations and government agencies that has explored several areas where crossing structures might be installed on roads to help wildlife and drivers survive.
Road ecologist Kylie Paul of the Center for Large Landscape Conservation said the group honed in on the Sixmile/Ninemile site because it met a lot of the criteria set in 2018 by the Montana Wildlife and Transportation Partnership, which includes the Montana Department of Transportation, Montana Fish, Wildlife & Parks, and Montanans for Safe Wildlife Passage.
The criteria rank locations by the number of species involved, the number of collisions that occur, and the public or protected land on both sides of the road, among others.
“The most effective way to reduce collisions is through wildlife crossing structures with fencing,” Paul said. “When you have fencing, that will pretty much reduce any kind of collision. But then, if you don’t have crossing opportunities, you cut off the wildlife movement. So the combination is required to keep wildlife moving and reduce collisions.”
After assessing the highway, the group decided the main crossing should take advantage of the old Sixmile Creek culvert, which is in bad shape after 60 years. The ends are obscured by vegetation, and the culvert is long, narrow and travels down a steep incline. FWP has identified it as a passage of concern for 20 years because it hinders fish passage.
The plan would be to build an “open-span divided bridge” by removing the broken culvert and a lot of the surrounding soil to create a somewhat triangular gap beneath both lanes of the highway. The bottom would be 75 feet wide, which would allow enough room for wildlife and Sixmile Creek to pass through.
The project would also take advantage of the East and West Ninemile bridges, where some wildlife already cross, but the terrain could be improved to aid wildlife travel.
Finally, wildlife fencing would be installed on either side of the highway for about 7 miles to guide the wildlife away from the highway and toward the crossing structures. Cattle guards would also be installed on highway access roads.
After working out the options, the Connectivity Group applied for a grant for a feasibility study and was recently the first project to receive a Montana Wildlife and Transportation Partnership grant. Starting in December, the Montana Department of Transportation will spend the next year or more conducting the study. But
Simon Buzzard, National Wildlife Federation Wildlife Connectivity manager, said next summer is the last round of federal funding from the Wildlife Crossing Pilot Program, which was created by the Bipartisan Infrastructure Law.
The group is hoping the study might have enough information by the application deadline to apply for federal funding. Paul said there’s a chance that Congress might extend the Pilot Program because it has bipartisan support. The group will also have to raise private funds to match any federal dollars.
“If the project is deemed feasible, then we’d move into a fundraising phase and hopefully break ground a few years from now,” Buzzard said.
One resident asked what the cost might be. Buzzard said because they’d be constructing an underpass and not an more expensive overpass, they’re thinking it might come out to around $10 million.
“That would be our ideal cost. Those federal programs require a 20% match so that’s not out of the question,” Buzzard said. “Some people have asked why now. There are a lot more people traveling on the road now. It’s maybe not our last chance to do something but in this area, if we don’t do something now, we’re going to lose that connectivity with wildlife across I-90.
Many species try to cross the highway near Cayuse Hill because it was a natural route to get to the Clark Fork River and move north-south.
FWP bear biologist Jamie Jonkel said he feels sorry for the local elk herd — which currently numbers around 350 — that often tries to cross because the highway severed their habitat. The interstate was completed in the mid-80s but the traffic has really amped up over the past decade to further limit wildlife movement. A few grizzly bears have also tried to move down along the Ninemile Valley over the years, Jonkel said.
“I’m super excited about this project. If you get on Google Maps and look at the way the terrain is in the Ninemile Valley, it will blow your socks off. You’ll see why this is such an important area,” Jonkel said. “All those wildlife coming out of the Missions and the Salish (mountains), they get into the Flathead River bottoms and come up on the Reservation Divide and the ridges lead right into the Ninemile Valley. So the crossing areas that these guys are talking about are perfect.”
