I don't remember too much about it, but believe it was back in the 30's that a thermal layer filled an entire valley with Carbon Monoxide and killed many. Phil
CO2 is heavier than air and sinks into the low point or valley. This trail was on or near the mountaintop, furthermore CO2 poisoning shows on toxicology tests so this was no type of gassing
Originally Posted by Dustyone
Originally Posted by Greyghost
Carbon Monoxide is nearly the same weight as air, and easily circulates with the flow of a breeze. As to the trail being near the top of a hill, not hardly.