I walked the original trail in Penrose, Colorado and they looked crazy to me. I grew up in Colorado and there are lots of great trails, but not all of them are "extreme." Colorado has unique wheeling.
(1) Mount Blanca Trail
(2) Holy Cross
(3) Red Cone
(4) Black Bear
Those are good as well. I forgot to put Blanca and Holy Cross on the above post for being fairly difficult. Red Cone has a crazy steep hill that can only be driven downhill. Black Bear is a great trail as well that puts you above the little town of Telluride with some amazing views of the valley and a great waterfall.
