Description. This strenuous loop with 300m (1000') of elevation gain can be run either way. Bring slime tubes, spares, or patches because you are bound to run into some serious spineage on this circuit. The trail bears some flood damage and although the original preferred direction was clockwise, many of the hike-a-bike sections are going to be uphill if you do the loop counter-clockwise, so perhaps this is a more aesthetic way to do it now - you will spend more time on your bike going downhill. We shall therefore describe the loop counter-clockwise. Begin in the canyon and head south into the Potrero proper, forking right 200m after passing the Spires on your right, as for the Nacimiento circuit. Turn right on a stony road after passing the rancho 'Los Pirules', and stay on it (avoid forking left 430m later as for the Yeso Rojo circuit). Pass a gate via a technical cow trail on the left, and continue uphill past abandoned gypsum mines. Where the road switchbacks right the second time, find a small trail that continues straight and follow it. The trail continues west and might be difficult to find at times due to damage and/or dense vegetation. Throughout, look for cairns and/or dots of red paint (look back from time to time too because the markings are meant for the opposite direction). After several washed-out arroyo sections the trail turns south and begins climbing more steeply, switchbacking into an arid, grey hillside through a maze of cow trails. Push your bike up the track that looks most used and you will top out on a plateau with good views of the nearby Illuminati Wall on the east face of Cerro La Palmitosa. Continue southwest and level for a short ways. After reaching the high point of 980m above sea level, the trail turns south-east and begins to drop heartily. You should be able to ride most of this section; there are only one or two serious washouts. The crux is keeping track of the trail - at times small rocks have been placed along its sides to help you, and rock barriers exist in places where one might easily go astray. Several times you will cross arroyos which are washed clean to the bedrock, providing for some difficult and bumpy slickrock sections. After a downhill with a deep rut and a final arroyo crossing, the Las Palmas singletrack joins the circuit from the left and the trail widens. Stay on the double track all the way down, or, just after a downhill section with red soil cut left into the Mesa de las Cuevas to descend the singletrack instead. Once you reach the main dirt road you can either return to the canyon via a swift downhill, or huff up another 15 minutes to wash your (by now itchy and scratchy) skin in the spring (see Circuit 1.)