In the rainforest of el Soconusco within the El Triunfo Biosphere Reserve, there are new trails winding through the 300,000 acre El Triunfo Biosphere Reserve. The main 10 mile hiking trail ascends the high slopes of Sierra Madre de Chipas into cloud forest and leads to a base camp filled with mystical moss, vines and orchids.
Note: Prior to 1997, the topographic maps developed by the federal government used the NAD27 CONUS datum. Starting in 1998, the government transitioned to the ITRF92 datum (some maps show both datum), which is pretty much identical to the WGS84 datum.
Overall, Sonja Bartlett is the 10th most popular hiking trail of all 11 hikes in Mexico.