The first three days involve a lot of driving, and not too much in the way of rocks. That's to be expected, however, when you're trying to get all the way from Michigan to Texas / New Mexico. So far we've seen mostly late Paleozoic carbonates and sands and some Ordovician dolomites. Many of the outcrops yesterday were nicely wetted by the rain for enhanced viewing, but we stayed reasonably dry and the rain had given up by the time we pitched our tents.
Today's been a long drive from the cool clouds of Oklahoma to the hot sun of Texas. As soon as we get gassed up and locate some groceries for dinner though, then we get spend the rest of the day exploring the fascinating geology of the "Grand Canyon of Texas", Palo Duro Canyon.