Long, technical, steep, pumpy -- what more could you ask for? Old Yellar is a great granite route that's technical down low. Then, midway up, you enter a vicious undercling to enter the steep second half with a heartbreak crux at the end. It's well worth the short hike to get up there.
This route has 4-star climbing with 2-star rock quality. Several key holds may not stand the test of time, particularly the key crimp where you move back left near the 2nd to last bolt.
Steepest route in the Front Range? The crux may be in figuring out how get a warm up for it.