Santa Ana del Valle, Oaxaca
From the city of Oaxaca, take any east-bound colectivo (Mex$20) originating from the sitio southeast of the Abastos market or bus departing from the main second-class bus station north of the Abastos market traveling along Highway 190 and going to Tlacolula or as far as Mitla. These same colectivos and second-class buses can be flagged down at the northeast corner of the baseball stadium (De Los Derechos Humanos and Eduardo Vasconcelos). Exit colectivos in Tlacolula at the intersection of Highway 190 and Benito Juarez, the main north-south street in Tlacolula, and buses at the main HPSA bus terminal, a block further south on Benito Juarez. Buses to Santa Ana del Valle depart from the HPSA terminal. Colectivos to Santa Ana del Vallecan be flagged down on 18 de Marzo, the north side of the bus terminal, or Benito Juarez heading north. Alternatively, walk north on Benito Juarez, crossing Highway 190, and flag down a buse and colectivo heading north to Santa Ana del Valle, brashly ignoring the sign forbidding loading and unloading of buses there. Both colectivos and buses will stop there.
Colectivos depart for Tlacolula at the corner of Pino Suarez and Morelos, getting off Highway 190, where a west-bound colectivo can be flagged down. Alternatively, buses depart from the HPSA terminal for Oaxaca.
Hike to Reservoir
The hike is about mile, or two kilometers, one way. Starting from the south side of the church, walk two blocks east on Pino Suarez until it ends at Morelos. Turn left and walk three blocks until Morelos intersects with Lázaro Cárdenas. Turn right onto Lázaro Cárdenas (now a dirt road) and walk for several blocks until it intersects with Plan de Ayala. Turn right onto Plan de Ayala and walk for about thousand meters, passing a water pipe on your left coming out of the mountains, until you come to a small, unimproved road on the left, unmarked. Turn left and walk uphill until you come to a fork in the road. Take the right fork and continue along the road until you come to trail that forks to the right. Take the trail until it comes to the reservoir. Before you see the reservoir, you'll see some low, concrete livestock watering tanks. Alternatively, you can just follow Plan de Ayala until it ends below the reservoir, at the creek flowing from the dam's spillway. If you do this, however, in the summer or early fall, when the rains are still falling, you'll have to ford the creek. Once you've crossed the creek follow the trail uphill for about 100 meters.