I beg to differ on the CO2... Here's from the status on their web page:
CURRENT STATUS: Measurements of the total discharge of carbon dioxide (CO2) gas at the Horseshoe Lake tree kill area range from 50-150 tons per day. Variations are primarily caused by changes in barometric pressure. There is no obvious trend of either increasing or decreasing gas flux at this area; we conclude that the total gas flux coming to the surface at Horseshoe Lake has remained at these relatively high levels since 1996. We do not have enough data from any other gas discharge areas around the mountain to draw conclusions about changes over time at those locations.

I was also visited there last Fall...It sure ain't getting any better... They have even had to close some areas of the ski area due to high CO2 levels...

Canie

• Long valley CO2 Status