Albi and Larry, two retired biking buddies who live happily in Oaxaca, set out one Monday in early March to test their strength and agility by riding along the aqueduct that carries water from a stream well up a mountain valley down to the water treatment plant in San Agustin Etla. This route is a perennial favorite among participants in the “Hoofing It In Oaxaca” program of weekly hikes and is equally prized by local mountain bikers. After registering and paying a nominal 50 peso permit fee, the two set out from the water plant and headed up the valley. The grade of the trail is quite mild, so the pedaling uphill was easy enough. More challenging were the narrow places where the trail balances on the edge of the aqueduct. There are also a number of spots where the trail jumps from one side of the aqueduct to the other. Most of these are bridged by planks of lumber which can be ridden over. The aqueduct terminates at a small water diversion dam in a mountain stream near the grand ruins of a hydroelectric plant built about 1900. From that point our intrepid duo continued onward, exploring a single-track trail that ran further uphill, generally following the stream. The trail had been recently groomed and marked for a mountain bike race, but even so the pair wished they had brought tools to prune back overhanging tree branches and clear brush from the trail. The riders decided to accomplish their return to San Agustin on a service road rather than retracing their uphill route, which made for a fast descent. All told, the ride covered 8.3 miles (13.4 kms), with an elevation gain and loss of 957 feet (292 meters). The outing began at the water treatment plant, which sits at an altitude of 6371 feet (1925 meters), and topped out at 6897 feet (2102 meters). The elapsed time for completion of the loop was just over two hours.