Hebgen Lake Dam malfunctioning. Evacuation?

I’ve just learned from Salle E. that something is wrong with Hebgen Dam near West Yellowstone and the area downstream is being evacuated due to flooding flows of the Madison River.

I see nothing on-line yet.

Update. Here is a news story. It looks like a gate is stuck open and a lot of water is flowing into the reservoir from heavy thunderstorms.

Link to Heben/Quake Lake area Google Maps

Update. Sunday. Sept. 7. Apparently this is still not fixed. Engineers are fashioning some steel “bulkheads” and so plug the headgates that became stuck open. Last week they were removing concrete from the water intake tower. After that the bulkhead will be lowered down. I believe the Madison River flows are still about 4 times normal for this time of year.

Note: this post has been superseded. See the more recent one.





  1. Ralph Maughan Avatar

    Thanks, Jeff. You posted just as I found another article. Yours is better.

  2. JEFF E Avatar
    JEFF E

    Thanks for the edit Ralph,
    I see that there is a winter weather warning for today and tonight from I.F. going north towards Yellowstone. A little early this year.

  3. SAP Avatar

    I am still sitting here in Ennis waiting for the wall of water. 😉

    Maybe locusts and the 4 horsemen will be along shortly, too.

    The river is up, but there is no word of evacuations. Evidently, EMS and FWP got RECREATIONISTS out of the river itself yesterday as flows went up, but nothing much else is going on.

    A big Sikorsky helo has gone by, but it may have absolutely nothing to do with the dam. Or, it could be involved in servicing the stuck gate.

    Everyone should take a DEEP BREATH and try not to turn this into a mini- “War of the Worlds” fiasco.

  4. Save bears Avatar
    Save bears

    My wife talked to her cousin that lives in that area a while ago, and he said the same thing, the water is up a bit, but nothing to really worry about, he said spring run off was worse..

  5. SAP Avatar

    Evidently there was some panic and some people chose on their own to evacuate. No evacuations have been suggested or mandated by any authorities.

  6. Lexi of Creative Energies Avatar

    Wrong, the sheriff’s department told me last night that they were evacuating residents on low lying flats along the river. And I personally know some of the people who were evacuated, such as the director of the Madison River Foundation and his wife.

    There was an earthquake yesterday, apparently under the dam or the lake, which caused the gate to malfunction. And they had a crew of 20 people pouring concrete at the dam last night.

    The sheriff’s department had Fish and Wildlife and the Game Warden assisting them in notifying people about the situation last night.

    The river currently remains below flood stage and does look muddy like during runoff. Not a good day to go fishing…

  7. Ralph Maughan Avatar

    Thanks to all of you for your reports on the Madison River. Please post if there is any change.

  8. Matthew Love Avatar
    Matthew Love

    I,m curious to the time of the earthquake due to the fact that my family and I were at the Quake Lake research facility and noticed nothing on the seismograph. Although the paper had been replaced. Please respond.

    Matthew, there was a microquake 1.7 at 7:18 AM. That is so small it is usually not felt. Here is a link to the data:


    Ralph Maughan

  9. Jeannie Stoddard Avatar
    Jeannie Stoddard

    We have a cabin on the lake and did not feel an earthquake. The lake is draining and when I called PPL (406-461-6936) they said that 2 gates have malfuncioned/fialed and they are manufacturing a steel plate that will be installed later today or tomorrow. The outflow has been 800cf and with the gate problem the flow has gone up to 3500cf (typical spring flow). They do not think the lake will drain down more than a few feet and feel that the dam is not compromised.

  10. Don Wilson Avatar
    Don Wilson

    Madison is closed to fishing from Hebgen to Ennis. If you go you will not be allowed access.

  11. Salle Avatar

    So I took a little drive around “the loop” of 191-287-87-20 and had a look at the scene. I was able to get below the dam and view the one gate that is open, the lower one, and it is definitely flowing hard. The little island downstream by Cabin Creek is under and it appears the water might be up by about 7-10ft above normal at that place. As my companion and I proceeded along the canyon toward Quake Lake we noticed that the roadbed is becoming undermine in places, like where the rocks always fall into the road.

    Near the easternmost part of Quake Lake there were some grizzly bears on the slope near the road, I only saw one of the cubs, it wasn’t safe to stop in that part of the road due to low visibility for upcoming traffic.

    Later on toward the visitor center there was evidence that the water was definitely high in the lake and there was an obvious current.

    The scene at the dam was interesting, lots of agency folk guarding the dam and discussing what’s happening. There was a large mobile crane at the far end of the dam but it is far too high up the spillway to access the door/gate that is stuck open. Even if they could get some attachment out t o the gate, it would topple the crane.

    As we passed by a raging flow along the remainder of 287 before the 87 jct, we noticed that there was an aircrane helicopter above us and circling the west end of the canyon. It didn’t look like it was going to be an easy task for that crane either. The canyon is narrow and there were clouds clinging to the peaks above, hefty wind in the canyon.

    As we drove over Reynolds Pass we noticed that it had snowed up on the peak starting at about 8500 ft. but the lady at the Tesoro station at the bottom of Targhee Pass said that there was snow on the ground right there this morning.

    When we returned to town a shop owner we were talking to said thaht he looked on the internet and saw that there had been an earthquake, about 1.7 I think, yesterday morning and it was located right near the dam.

    ‘sall I know…

  12. vicki Avatar

    I hope all the people in the area are okay. Since New Orleans is once again becoming submerged I doubt this will get the attention it deserves. Take care to all in the area.

  13. Lexi of Creative Energies Avatar

    One of the workers on the dam told my neighbor they were doing a routine release when the whole dam began to vibrate. That took out the hydraulics for the problem gate. The flow went from 900 cfs to 3000-4000 cfs. The vibration then subsided.

    May have been an earthquake, but I do not know the exact time this happened. We have many small quakes and it is common for people to not even notice them.

    Yesterday friends of mine were fishing by that island at Cabin Creek. She had waded out to the island and saw water going up fast. She retreated to the riverbank as water rose a foot very quickly, quite muddy. Alarmed, they left. This was a little after 1 pm yesterday. They stopped at Slide Inn to ask what was happening but no one knew anything about it.

    A capable friend of mine worked for awhile on the committee planning the emergency response to a potential dam failure about two years ago. The only thing the committee focused on was how to get emergency personnel in there. They refused to concern themselves with how to inform the public, despite repeated efforts of my friend to address the issue.

    I don’t think they are trying to hide information, but they plainly are not making the effort to keep the public fully informed. Communication needs improvement!

  14. Ralph Maughan Avatar


    The quake was at 7:18AM on Sunday.

  15. Eve Avatar

    We drove by the north shore of Hebgen Lake yesterday, noticed LOTS of vehicles at the dam and the large amounts of water being dumped down the river. We wondered if there was a problem at the dam and did an internet search almost the moment we got home. There wasn’t much out there last night, but I found this article this morning…


  16. Lexi of Creative Energies Avatar

    Interesting article. I live right in town and no one came to our door or I certainly would have gone to that meeting.

    Definitely need improvements in communication.

  17. Salle Avatar

    Somehow, it doesn’t sound like they had all their ducks in a row on this one at any given time…

    Proud and happy my hind foot…

  18. lww Avatar

    does anyone know if the probelm has been fixed or are they still letting all the water down the river?

  19. Ralph Maughan Avatar


    Here is the latest AP story. Sept. 4.

    Bulkhead to plug 2 broken headgates

  20. Maria Evener Avatar
    Maria Evener

    There is an AP article on the Bozeman TV Station…(KWYB) website regarding the bulkheads not working. Also commentary on http://www.mrfc.com/MadisonRiverMontanaFishing/MadisonRiverReport.aspx

  21. Ralph Maughan Avatar

    Thank you, Maria.

    I added your information to the latest post. This thread is now closed.

    Folks, use the latest post.


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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