Sometimes, the obvious escapes me. I have found throughout this adventure of trying to piece together a story from historical documents and family stories, that time and again, an answer has been staring me in the face without me seeing it.
Now, I'm trying to put together maps to post to the website in order to make hiking easier as well as to put the tramway in context with the mine it served. Up until recently, I have not been able to find a map of the Mexican side. All USGS maps seemed to end at the border.
Fortunately, I recently bought a USGS map titled "Boquillas: Texas-Coahuila. 1:100 000-scale metric topographic map." Item #29102-A1-TM-100. 1984, Geological Survey, Department of the Interior. Amazon.com says it's out of print.
It's the first topographic map I've found that extends over to Mexico in this area. The Puerto Rico mine is located on the map! Now that I know where the map is, I can understand why the Puerto Rico mine owner's son had never heard of the tramway. By the time his dad had taken over the mine in 1928, they were using mule trains to haul the ore to the train at Quatro Cienegas. The terminal was five miles away and was probably over the side of a hill he never bothered to peer over.
While the Aerial Tramway is clearly marked on the US side, it's not on the Mexican side. But, if you extend the tramway's line on the map for the equivalent of 2 1/4, which is the distance covered on the Mexican side as noted in the February 1911 article, it ends right in the middle of a canyon and about 3/4 of mile away from a dirt road that ends at the line and goes to the Puerto Rico mine.
Then, it hit me. The mountains that appear just west of the aerial tramway line that I drew into Mexico are labled "Seirra El Terminal!" The Terminal Mountain Range!
Clearly, the mine and tramway were important to Boquillas, Coahuila if the name of the mountain range that's along side the Mexican portion of the tramway is named after the terminal. And now I have a good idea of where to look for the embarkation terminal, if I ever get over to Mexico. What was once mysteriaous is all so obvious, now that I have the map.
And all the while, my kids have been watching Dora the Explorer with them asking, "Who's the one you need to know if there's a place you need to go? Right, the map!" Simple.