Saturday, May 25, 2013

Stay On The Boardwalk!

I don’t know about you, but I am totally astounded whenever I see anyone step off the boardwalk at Yellowstone’s hot springs. As a summer seasonal park ranger I see this behavior all the time and can’t help but wonder. What are these folks thinking? 

Last week I came across a perfect example of why it is best not to consider doing anything so foolish. 

IMG_5037 Collapsed Travertine
Good Godfrey!  Collapsed travertine at Mammoth Hot Springs

I was in Mammoth Hot Springs finishing up a week of training before the summer season gets going in full swing. I’d wanted to see the famous travertine terraces in Mammoth and finally had an opportunity one day after class to stroll about Canary Spring with some co–workers. 

IMG_5034Sacha AndBrian
Taking a stroll at Canary Spring

Although Mammoth is outside the boundaries of any of Yellowstone’s three famous volcanoes, a network of fractures and fissures still form a plumbing system through which hot water percolates to the surface from deep underground. Frequent small earthquakes serve to keep this plumbing system open.
And since Mammoth is outside of the boundary of the volcanoes, it’s bedrock of limestone was never blasted into eternity like the bedrock inside the caldera. This ancient limestone is the reason the Mammoth terraces exist. 

IMG_5043 CanarySpring
Canary Springs

Heated groundwater combined with dissolved carbon dioxide in the limestone creates a weak solution of carbonic acid. As this solution rises through the bedrock it dissolves calcium carbonate, the primary compound in limestone. When this dissolved calcium carbonate hits the surface it precipitates out of solution and is deposited in the form of travertine. 

IMG_5038 Collapsed Travertine
Collapsed travertine deposits at Canary Springs

So you think it's okay to walk off the boardwalk in the hot springs? Do you really know what is underneath that thin crust?

Perhaps visitors are not quite aware of the concept of dissolving rock capable of leaving underground voids and empty spaces which can then collapse with the slightest weight from above. 

If people understood this, I wonder if they would still step off the boardwalk. Ultimately, they are not only destroying a fragile resource but they are also putting themselves into some serious danger. 

IMG_5039 MammothTerraces
Mammoth Hot Springs Terraces


  1. I've been taking school groups to that spot, its a perfect example! Did you guys happen to see a bull snake while you were up there? We've been seeing a pretty good size one on the way down past minerva springs.

  2. May be time for a new interpretive sign. Unfortunately, only about 10% of people read signs. Would have to be kind of a scary picture of someone sinking into the hotsprings.

  3. This looks awesome - we loved the volcanic landscapes of New Zealand and have to check this out too!