Herrington trail is a singletrack that comes in two sections, North and South. <br />
The South section connects Spring Creek trail to Stout trail and then to Towers trail/road with a climb of about 200ft. A short bit of Towers trail/road then connects to the north section of Herrington, which continues down to Loggers trail, giving back the elevation gained of the south section of Herrington. Herrington offers some interesting singletrack alternatives for creating loops in HTMP. The south section seems to get less traffic than the north section, which results in an even narrower trail.
Horsetooth Mountain Park
http://www.singletracks.com/item.php?c=1&i=7379