World's biggest beaver dam discovered in northern Canada

The dam is over a half mile long-

World’s biggest beaver dam discovered in northern Canada. by Michel Comte and Jacques Lemieux. Yahoo News.

Regarding beaver locally (near Pocatello, ID), today I went up to check on the big beaver ponds below Scout Mountain. I found some ATV vandal today or yesterday had ridden the ATV all over the soft mud and meadow next to the ponds, deliberately making a big mess in a vehicle closed area.






  1. SEAK Mossback Avatar
    SEAK Mossback

    Actually, I think a pond in a system where I work has a dam that’s over twice the length of this one, judging by some quick measurements on Google Earth. It’s not all continuously active dam as the beavers concentrate for periods of years or decades on sections that are lower and weaker points at any particular time. Basically, they cordoned off and flooded an area against the mountainside on the inside bend in the river, with the dam following along the river bank for about 1.3 miles encompassing over half of the perimeter of the pond (actually a complex of basins fed by small streams coming off a steep mountainside) and surrounding marsh. It’s nowhere near as high as many of the dams I’ve seen in interior B.C. but I think would qualify as a continuous dam.

    I’m not sure the economic value of what beavers do is really appreciated. In one particular year in the 1990s, I estimated the landed ex-vessel value realized in the commercial fisheries from the coho smolts that reared and swam out of that pond the year before, survived in the ocean and were caught on their way back at conservatively over $61,000 for over 8,000 adults caught, plus another 125-150 taken by sport anglers. Not including any estimate for the sockeye also reared in that pond , or the sea-run Dolly Varden and cutthroats that migrated out and may have been caught by somebody somewhere.

    I doubt any of the people who catch those fish, either on the open ocean or in the various straits and passages, have ever seen that picturesque little pond with its pair of nesting swans or have any idea how they’ve personally benefited over the years from the volunteer workforce patrolling and patching that dam day and night. I wouldn’t be a bit surprised if beavers produce more coho salmon than all the hatcheries on the Pacific coast. (OK, now I’m starting to sound like Pierce Brosman with his public promotion of beavers in the movie “Grey Owl” – “You’ve got a flood control system a thousand miles wide!”)

  2. Devin Avatar

    Just curious, is the closed off area at Scout you mentioned the area right before the Nordic area turn? That area has made a great comeback in the couple of seasons now that it has been closed that it is sad to hear someone’s been through and ripped it up.

    1. Ralph Maughan Avatar

      Hi Devin,

      I called the Forest Service today, although it is on Idaho state school endowment land.

      One guy in a 2 x 4 drove in and got stuck. He got a ticket. An unknown person in a 4 x 4 drove in and made a big mess on the closed muddy road.

      Another unknown person drove an ATV all over the meadow next to the ponds.

      I believe they are going to haul in more boulders next week to block illegal ingress from the Scout Mountain road.

  3. Nancy Avatar

    SEAK, I have a nice stream running thru the valley I live in but because of all the water rights attached to it by ranchers, you never see any beaver dams. Although I do recall one years ago on the meadow across from me (this rancher was kind of lax about those things)

    The pond was quite beautiful but, (and I’m only guessing here) peer pressure came into play, the trapper came round and the backhoe showed up the following spring and everybody was back to getting “their” percentage of water for irrigation.

    Had a friend close to town have a beaver show up one spring and build a dam on an irrigation ditch next to her. It soon got ripped out but, being the superb engineers they are, it re-built. She had no problem with the little guy (even though her yard got flooded) but the dam got ripped out again and unfortunately so did the builder………

    I do wonder about how their numbers are faring, what with all the trapping going on and the ranchers that can’t appreciate a “stock” pond here and there.

  4. ProWolf in WY Avatar
    ProWolf in WY

    That would be incredible to see.

  5. Linda Hunter Avatar

    For years people who work in the logging industry have been telling me that without clear cutting the elk would have no place to graze. There are some natural meadows in the forest that it seems the elk prefer, though, and when I looked into how they were created it was historic beaver dams which made them.

  6. ProWolf in WY Avatar
    ProWolf in WY

    Amazing how nature was able to take care of itself for millennia before people came around, isn’t it Linda?

  7. SEAK Mossback Avatar
    SEAK Mossback

    Nancy, your case brings the realization that not everybody appreciates beavers and they don’t fit in everywhere they used to. People don’t want their water impounded, their road or property flooded or trees dropped on their power line. But what better place to enjoy a spring day than on a beaver pond in the midst of a wetland, where so much life comes together?

  8. Alan Gregory Avatar

    A beaver dam in Vermont burst a few days ago, causing flooding in a small town. Here’s a link:

  9. Nancy Avatar

    That meadow plus rights to the creek (about 30+ acres) just went on the market. Maybe we could hold a pot luck dinner & a silent auction and raise enough funds to let it go back to nature? Probably to small for the NC to consider……..


Dr. Ralph Maughan is professor emeritus of political science at Idaho State University. He was a Western Watersheds Project Board Member off and on for many years, and was also its President for several years. For a long time he produced Ralph Maughan’s Wolf Report. He was a founder of the Greater Yellowstone Coalition. He and Jackie Johnson Maughan wrote three editions of “Hiking Idaho.” He also wrote “Beyond the Tetons” and “Backpacking Wyoming’s Teton and Washakie Wilderness.” He created and is the administrator of The Wildlife News.

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Ralph Maughan