In west Texas through hill country. Nice following wind today, but yesterday had many steep hills and side / head winds. Schwalbe Marathon tire on back is delaminating. The nearest bike shop I know of is in El. Paso. Hope I make it. Doing roughly 65-67 miles daily.I take it that's a Marathon and not a Marathon Plus. I had bad luck with a Marathon on the TransAm it wore down to the brown stuff and started getting flats after about 2K. My helpful companion told me I should have put new tires on before I started. (I had) Someone once told me that NASA has done a study and found that things generally last a lot longer than you think they're gonna. That could be BS but I've found that in general stuff wears slower than you think. So fingers crossed. I don't know your schedule but you could get a tire sent to a post office a few days ahead. I had good luck with that when I found my debit card had expired in the middle of the NT.
Stay upright. Pete