Today a bunch of us piled into two jeeps and went jeeping. I’d never been and looking at the jeep trails, I was not convinced one could drive through them, even in a jeep. I was proven wrong and I’ll admit it was loads more fun that I expected. And, bonus, there are places you can really only reach by jeep unless you want to take all day (or week) hiking there.
I managed a very short little wander through the woods at 9300 feet without any ill effects, so maybe my lungs are adapting.