Beavers are, by definition, rodents. That classification, though, might not do justice to the semiaquatic creatures, often called “ecosystem engineers” by biologists. In Montana, for instance and according to the National Wildlife Federation, beavers create wetlands that support more than 80% of the state’s wildlife..
For decades, problematic beavers that created dams in inconvenient places for humans were trapped and relocated — or worse. But removing one of these engineers from the landscape was never a long-term fix. Soon, another beaver would come along and rebuild. Elissa Chott, the National Wildlife Federation’s Montana Beaver Conflict Resolution Program team lead, said building dams is a natural instinct that beavers cannot simply turn off.
“A roadway over a creek or a ditch is really just a dam in the eyes of a beaver. And a culvert under that roadway is a hole in that dam,” she said. “So the beaver’s instinct is to just plug that hole.”
About a decade ago, several stakeholders in western Montana came together to discuss issues related to beavers. Beaver dams occasionally wreaked havoc on roadways and property, but those involved, including Montana Fish, Wildlife & Parks, recognized the animals’ importance to the landscape.
Torrey Ritter, a wildlife biologist for FWP, said beavers have played a role in shaping the landscape since long before European settlers arrived in the region. The dams they build direct waterways, replenish groundwater and create wetlands vital to wildlife. Ritter said that one beaver family (which can include just a pair of beavers and their children, and go up to 10 or 20 in some cases) can help develop an entire ecosystem by constructing and maintaining more than 20 dams in an area.
“A roadway over a creek or a ditch is really just a dam in the eyes of a beaver. And a culvert under that roadway is a hole in that dam. So the beaver’s instinct is to just plug that hole.”
— Elissa Chott, National Wildlife Federation
In 2019, the National Wildlife Federation launched a pilot project to reduce the impact of beaver dams on humans. Chott said the project replicated those found elsewhere in the country, particularly on the East Coast and in Washington and Oregon. Some efforts are as simple as wrapping a tree with galvanized wire fencing to prevent a beaver from chewing down the tree and using it as dam-building material. Other efforts involve installing fences around culverts. Chott said that beavers are attracted to the sound of moving water, so if they can be kept away from that sound, they’ll take their dam construction elsewhere. Sometimes, building fences just a few feet out is enough to be effective.
Perhaps the most intricate type of installation is a pond leveler. A pond leveler involves installing a high-density polyethylene pipe through the center of a free-standing beaver dam, allowing water to pass quietly. The water level will then drain to the height of the pipe, but the beaver won’t notice that not all the water is being held back.
“We kind of use their little quirks against them,” Chott said.
Since the project began in Montana, there have been nearly 100 installations, Chott said. The project’s coverage area has also grown, generally following the various FWP regions. In the early years, Chott was the only beaver conflict prevention specialist serving Missoula and the surrounding region. In 2024, the program added seasonal specialists in Bozeman and Great Falls, and this year, one was added in Kalispell.
Chott said the program’s services have been utilized by private landowners as well as state and federal agencies. The program, which is funded by the National Wildlife Federation and some federal grants, typically covers half the cost of materials, with landowners asked to pay the remainder. The program also covers the labor required to install solutions, whether a tree wrap or a pond leveler.
Ritter said the program has been successful because it lets FWP focus on other wildlife issues and allows the beavers to play their natural role in the landscape.
“One of the really cool things about this program is that we can keep these ecosystem engineers working,” he said.
For more information about the Montana Beaver Conflict Resolution Program, call its hotline at (406) 393-5557.