12/23/2011

Earthquake Lake - Part One

I don't know how things work for you, but I have this terrible habit of exploring everything but my own 'backyard'. Of course I have amended this in many ways while living at Elk Lake. In fact, I know as much of my backyard as can be reached on foot from the lodge quite well.
However, in Montana 'backyard' is often defined on a much larger scale. In fact, when you realize we consider folks in Island Park, Idaho and West Yellowstone, Montana and even Dillon and Ennis, Montana "neighbors", well, maybe the idea is coming clear.
So, in keeping with my amended ways, I have spent a bit more time exploring my more extended backyard. In recent posts I have shared trips to Virginia City and Nevada City (just over the hill from Ennis and a workable day-trip from Elk Lake). I have shared our excursion on Lower Red Rock Lake (I shared an adventure on Upper Lake months ago). And, while I cannot see Virginia City and Nevada City from Elk Lake, I can see Upper and Lower Lakes and Earthquake Lake (known around here as Quake Lake) from a nearby high point. This, alone, makes them seem closer to home.
Thus late this summer I stopped by the Earthquake Lake Visitor Center and took a look around. Having driven past several times in the past, I was surprised at how much I had missed. Not only does the Visitor Center offer a plethera of information, the auto tour along 287 and the walking tour at the Visitor Center offer much to enlighten those who slow down and look.
As I mentioned in an earlier post, my interest in the Earthquake which caused such devistation in 1959 really began in the Virginia City Museum. Some of the historic photos I will share in the next two posts were found there. Others came from the Visitor's Center. The map shown above highlights the primary 'points of interest' on the driving tour.
The auto tour begins at the spillway. This spillway was created - in a hurry (which still took two months) - by the Army Corps of Engineers. When the mountain slid down and blocked the Madison River, it set into motion a couple dangerous scenarios. One, the rising waters threatened businesses and homes upstream. Two, no one knew how much pressure the new 'dam' could handle. Granted it was a mile wide and more than half a mile through, but at some point the water, if left alone, would overtop it. Then what? Would it break through and send a massive flood into the Madison Valley and downstream to Ennis?
No one knew for sure - and therein lay the danger. So, they made the decision: Build a spillway and release some of the pressure. Thus began the work on the original channel - 250 feet wide by 14 feet deep. By Septmber 17th, water once again flowed into the dry riverbed below the landslide. Yet the engineers were not content. The channel needed to be deeper. Therefore the Army Corps deepened the channel to 50 feet, a project they completed on October 29, 1959.
The third point on the auto tour offers one a beautiful view of the lake looking Southwest. The dead trees stand in mute testimony to the devistation caused by the lake's rising waters. While the water level is slowly dropping (as the channel cut by the Corps of Engineers erodes), at the time the auto tour brochure was printed, the lake was 6 miles long and 190 feet deep.
Not only is the auto tour beautiful; not only does it tell stories hard to imagine; it also offers a lot of interesting scientific information. This particular sign, in part, says: "At 11:37 p.m. on August 17, 1959, a 7.5 earthquake shook this area and triggered a massive landslide. Rushing currents of the Madison River were blocked and churned behind the massive rock dam created by the slide. The water rose quickly submerging Rock Creek Campground by 6:30 a.m. the following morning. The landscape instantly changed, lives were lost, and a lake was formed. The eerie trees you see in the middle of the lake are reminders of the dynamic forces which formed Earthquake Lake."
There were 250 people in the canyon that night. They went to sleep carefree. They woke trapped! The situation went from bad to worse. Imagine the noise. The terror. The pandemonium. The DARK! In the confusion people headed for high ground. Only as the night wore to an end would they learn not only could they not get out, rescuers could not get in!
Injured people needed assistance. Fortunately one person trapped on this high point was a nurse who had just completed a trauma first aid class (for more about this heroric woman, I recommend the book "Cataclysm" which I reviewed in my last post). However, as sunrise shed its light upon the scene, Forest Service smoke jumpers were finally able to parachute in to assist with the injured.
While the current Cabin Creek Scarp area, next stop on the auto tour, is much too beautiful to imagine the destructive forces which formed the 21 foot vertical displacement shown above, this historic photo shows the dramatic shift in the earth's crust which occured that fateful night.
Rising water - Destroyed roads - Displaced vacationers - Homeless residents. These were only part of the problems found at daylight. Not far from the earthquakes epi-center, and just upstream from the massive slide, stood the Hebgen Lake Dam. This earthen dam had sustained substantial damage - how much no one really knew. In the end the dam would hold. If it had not - well, the story could have ended much differently!
Imagine you are carrying a flat pan of water across your kitchen. Just before you reach the sink, you bump your elbow. What happens to the water in your pan is exactly what happened (on a much grander scale) to the water in Hebgen Lake. In some places the ground dropped 20 feet. The shifting ground created tidal waves which surged over Hebgen Dam and overcame anything within their reach. It took at least 12 hours for the waves to subside. Thankfully the dam held.
But, the earthquake not only caused the lake's bottom to drop, it also tilted the land under the lake. Back to our pan of water illustration, not only did you bump your elbow, but in reaction to the pain, you raised one side of the pan. Hebgen Lake's north shore raised 19 feet! So much for lakefront property!
The next stop is called "Building Destruction". I must admit, the name was less than inspiring - in fact, it seemed quite boring. However, the story told on this sign is less than boring. In fact, it is downright amazing!
As one might expect, many buildings were destroyed during the night. However, one of the most unique stories is of a woman whose home was dumped into the lake. In fact, her dog may be the real hero of the story.
The final photo from our auto tour is a historic shot taken where the Red Canyon Scarp destroyed a section of Highway 191. Thankfully no one in the car was injured when the driver plunged off the unseen six foot dropoff.
In my next post I will share more photos and information from my explorations around this dramatic natural disaster which nature has again returned to an amazingly beautiful, tranquil setting.
I find it hard to believe this is just another one of the things I find in my big backyard!
Lady of the Lake

No comments: