Aerial Image of Wildlife Overpass

US 93 North Wildlife Passages

wildlife crossing structures map If you’ve driven the stretch of U.S. Highway 93 on the Flathead Indian Reservation, you’ve likely seen the “Animals’ Trail”, a 197-feet wide vegetated bridge that provides safe passage for wildlife to cross over the busy highway. That Animals’ Trail may be the most visible, but it’s just one of dozens of fish and wildlife crossing structures that line the 56-mile stretch of highway. In total you’ll find:
  • 41 fish and wildlife crossings (including the Animals’ Trail)
  • 60 jump outs
  • 2 underpasses for livestock
  • 1 bicycle/pedestrian underpass
  • 18 miles of wildlife fencing
  • 8.7 miles of road length with wildlife fencing on both sides

The Montana Department of Transportation, Confederated Salish and Kootenai Tribes, and Federal Highways Administration constructed these passages to improve safety by reducing wildlife-vehicle collisions and to protect wildlife migration corridors.

The structures are located in areas known for heavy wild life crossings and mortality, and/or locations where the surrounding landscape was best suited for the structures. Typically, you can find them near stream crossings and areas with protected habitat on both sides of the road.

Fish And Wildlife Underpasses Thumb

Fish and Wildlife Underpasses: The culverts and bridges are designed to provide safe crossing opportunities under the highway for wildlife. Structures that include a stream aim to resemble natural stream conditions for fish and other aquatic species.

Aerial Image of Wildlife Overpass

Wildlife Overpass: Some large carnivores, deer, elk and moose tend to use vegetated highway overpasses more frequently than wildlife underpasses to access the other side of the road.

Animal fencing

Fencing: Eight-foot high wildlife fencing on both sides of the road keeps wildlife from entering the highway and directs them to crossing structures.

Wildlife fencing jumpout

Jump Outs: Jump outs allow wildlife to safely jump down to the other side of the fence should they be caught in the fenced road corridor.

Wildlife fencing with crossing guard

Wildlife Crossing Guards: Modeled after cattle guards, wildlife guards discourage deer and other hoofed mammals from entering the fenced road corridor at access roads.

You can find dimensions of each of the wildlife crossing structures in this table. Part of the success of wildlife crossing structures comes from animals feeling secure in approaching or crossing the structures. We appreciate your interest, but please do not approach or enter the wildlife crossing structures; it is not allowed.

The following table details the types and dimensions of the underpasses on US 93 North.

TypeSize in FeetNumber
Cement culvert10 x 141
Concrete box culvert5 x 73
Concrete box culvert6 x 45
Concrete footers/divided lanes12 x 221
Conspan arches9 x 282
Conspan arches northbound and southbound14 x 431
Corrugated metal arch culvert12 x 241
Corrugated metal arch culvert12 x 222
Corrugated metal arch culvert17 x 244
Corrugated metal arch culvert24 x 132
Corrugated metal arch culvert24 x 15.52
Corrugated metal arch culvert6 x 41
Corrugated metal arch culvert8 x 81
Corrugated metal pipe or concrete box culvert7×51
Corrugated metal pipe or concrete box culvert12 x 227
Multi span bridge (existing)1
Open span bridge15 x 39510
Open span bridge10 x 1001
Open span bridge12 x 1001
Open span bridge16 x 1311
Plastic coated corrugated metal culvert6 x 42
Wildlife overpass49 x 1971