You must have missed to interpretive sign along the trail that talked about the railroad having to break the trains in smaller units and using of helper engines to climb out of the valley onto the western plains. We made that climb at the end of the day after traveling from Houston on the eastern end. I was expecting it because I had read the sign, but my wife was more than a little suprised with the length of the climb. Not a bad climb, just a long one. The return trip back east was fantastic. I think I only made a couple of pedal revolutions in 5 miles.