We made it about 60 miles into Colorado today. There's an amazing spot where Rt. 76 crosses from Nebraska to Colorado. For 300 miles the terrain in NB is flat, green, and irrigated farmland from one horizon to the next. Then you cross into CO and within the first mile you're surrounded by brown, rolling pastures and grazing has replaced farming. The Midwest became the West in an instant.
Traveling went well except for 20 miles of "singing highway." The road surface made this odd buzzing drone that kept shifting in pitch. It was like listening to a chorus of chanting monks perform John Cage.