Chief Mountain rockfall - 1972

[llholmes1948]

I wonder if anyone knows if there have been any major rockfalls from Chief Mountain after the major one that took place in 1972. I recall that news of a major rockfall from east side of Chief Mountain spread through the park quite quickly and I learned about it when I was at work at Lake McDonald Lodge. The rockfall was witnessed by a number of people including some who had stopped at a turnout near the mountain and a couple of Lake McDonald employees on their way to Waterton on a day off. They described it as a piece of the mountain as big as a house breaking off and tumbling down. As I recall in the next issue of the Hungry Horse News, Mel Ruder published some before and after photos of the mountain. Chief Mountain is pretty large and I think you had to look carefully to see what was missing. Most of the mountain was fortunately still there.

I have a vague impression that the rockfall occurred in the morning and I learned about it late morning or in the afternoon. I believe it was on a nice sunny day. I would be interested to know if my memory is accurate in this regard or if it has become fogged over the years by working too hard and raising children.

Fortunately J. Gordon Edwards gives us the exact date in his climbing guide (1995 edition Page 135) which was July 31, 1972. He describes it as follows:

"On July 31, 1972, thousands of tons of rock fell from Chief Mountain as the entire northeast corner collapsed. The roar was heard as far away as Lake McDonald and the dust cloud was seen from Ptarmigan Tunnel and Granite Park ."

It is hard for me to believe that this rockfall was actually heard at Lake McDonald (I certainly didn't hear it but I was inside the hotel.)

This link mentions rockslides in the plural so perhaps there have been other major rockslides since 1972:

http://www.nps.gov/glac/naturescience/u ... %20Mtn.pdf

Lyman

[Calgary Ray]

Lyman:

The second landslide/rock fall at Chief Mountain was July 1992, when a chunk of the north face fell away. There had been a moderate earthquake recorded in the area on July 2, about 4.2 on the Richter scale, and the missing chunk on the mountain wasn't noticed for a week or more (you gotta wonder if the red bus gearjammers had quit caring so soon).

Geologists also figured that heavy rains and freezing night temperatures may have loosened that section of the mountain prior to the quake.

If you look at photos pre- and post-1992, particularly those taken from the overlook on Chief Mountain Highway, the missing chunk on the lower part of the mountain is quite stark, as if someone took a scoop and carved out a piece.

[ManyGlacierSean]

I thought I would provide some visualization of the northeast debris field in discussion... we counted 14 little lakes in the debris field, which seemed spread over a mile away from Chief. Gordon Edwards I believe talked about a 1954/56(?) event in addition to the 1972 event. Mid-50s, 1972, 1992... we are about due for another one! Some of the boulders down in the debris field were huge, one looked to be nearly as big as Many Glacier Hotel itself. Interesting to note is the ring of dead trees around the debris field... I am guessing that they have died due to a relatively recent lack of moisture caused by the slide event(s). I would really like to get a Blackfoot permit this season and venture around down there...

[RKoester]

I drove on the East Side last week and wanted to take a some pictures of Chief Mountain. Thought I would read up on it a little before I went. Found this post about the 1972 rockslide. I can share a little information on it.

I was driving bus that year. At the end of July, three of us (me--Bob Koester, Doug Cook, and Chuck Carlson) decided to climb Chief. We used the old oil road from the north, which in those days was not posted and was open. We climbed the back side. As we approached the mountain, we heard rocks falling, not big ones, as if some people ahead of us were tossing them off the top and they were crashing below. That's all we could guess they were.

About half way up a quick storm passed over and we heard St. Elmo's fire and waited until the sound stopped. The sky cleared. We continued to the top and rounded the corner to reach the summit. At that point we looked down the front side and saw a white cloud passing in front of the face. It was one of those odd thing. The storm had passed. I should have taken some pictures.

It was a great day at the top, no wind, perfect temperature, blue sky. We climbed down the way we came. Nearing our car, I looked back and took a picture of the mountain. The north east corner seemed to have changed shape a bit; a hollowed out areas was there that hadn't been there that morning. But we didn't think any more about it until we got back to Lake McDonald lodge and were told that a major rock slide had taken place on Chief Mountain.

About two weeks later another Jammer, Jim Erickson, was with a tour on the overlook, telling about the rock slide two week earlier. Right then another huge chunk came off. As always, Jim had his camera in hand and caught the white dust cloud passing in front of the face. He took a series of pictures, which were under the glass at the Many Glacier info desk until the end of the summer. Seeing those pictures was the first time we made sense of what we had seen from the top.

The Hungry Horse News reported the slide that took place when we were on the mountain. Supposedly it was heard at Lake McDonald, but we were right there and heard nothing. Perhaps the mountain covered the noise.

Thanks for the initial post. Hope you are still getting replies these many years later.

Bob Koester

[llholmes1948]

Bob,

Thanks very much for sharing your recollections of this incident and I remember that it was the talk of the park for a while. As I said previously I was working at Lake McDonald Lodge that day but I did not personally hear the rockfall and I don't recall any other employees at the Lodge saying that they did.

Lyman