Wow- I am also in San Antonio and I am also riding this route (more or less) this summer, only in reverse, as the homeward leg of my tour. My friends are in Arizona and my west coast destination is my brother in San Francisco. Thank you, Jamawani, for your response! I came close to Yellowstone on a previous tour and have said to myself ever since,"next time". Your information is just what I need to proceed with an even greater degree of excitement, from the point of view of an experienced bicyclist. I am eager to ride Death Valley as well, as my brother rode it in the 90s and made it sound incredible. I recall he had a sign on the rear of the bike, H20?, inviting cars to stop and offer water, which I found clever. Sharpshin, have a great trip- maybe we'll cross paths in the desert!