There's at least 3,500 ft. of climbing and no place where it flattens out for recovery. I usually take a few breaks to catch my breath when I need one. You'll love the fast ride back down; watch for bad pavement. The wife and I drove the SUV over the Clockum Pass last year from Ellensburg and found it to be very rough, poorly marked, and long. There may be better and more direct trail between the towns though.