[Bubba Ho-Tep]

Not sure about that exact location, but there's a fair amount of volcanic activity in that area, in the form of hot springs and vents. Near Mammoth Lakes, there's a spot where all the trees have been killed by CO2 venting from the ground and 15 years ago three ski patrol guys were killed when one fell into a vent that had opened under the snow and the other two when they tried to rescue him.

[pfflier]

Sure looks like a likely culprit. You would think the trees would love CO2 but too much of anything can be toxic.