The air is so thin. We ran a little dirt trail around Yellowstone lake early in the morning. We ran until there was a warning sign that a bear was frequenting the trail we were running down. And since a man was killed by a bear here last week, we turned around. It felt so hard to catch a good deep breath. But the crystalline lake, sparkling blue water, green pine trees and multitude and variety of wildflowers kept me in awe. Yellowstone has been amazing. | 