Back to the Horsetooth Mountain Ride map.
Can you say "yikes"? This is one of the trails that I have marked with the Haz Waste symbol. It is one of the most technical, rideable trails I've ever seen. I have seen a riding partner ride this sucker, otherwise I wouldn't even list it as a cycling trail.
The trail follows the wash of the upper end of Spring Creek, which is always dry in the Summer, Fall, and Winter months. It twists down through erroded granite notches barely wide enough for your cranks to pass, drops off often and deeply, and is generally NOT for the hesitant rider. If you like your riding to be tough and techy, and you don't mind some contusions and lacerations, this is your kind of trail.