This is really a hiking trail but gives you a way to get down to the bottom of Pueblo Canyon. Expect to be off your bike frequently on the middle section.
The trail begins from a small pullout to the north of NM502, just east of Eastgate Drive. Go through the pedestrian opening in the barbed wire fence. The first 1/2 mile is rideable until the mesa ends and the trail descends via sharp switchbacks and then loose slopes. At the bottom you should be able to ride the last half mile to the Pueblo Canyon Utility Road.