this H11 B32 map from the full coverage 50k scale series is suppose to be the correct one for erendira and the mine -if you pull it up yourself you can use the appropriate magnification to view good resolution closeup

-erendira should be in sw corner -where it says bonca erendira or something-for some reason unknown to me they have been using Puerto San Isidro as another name for Erendira area -
I've never been there and dont speak spanish so makes it harder to guess and too time consuming to translate everything- once I find the info in this set of map series its another 19 to 29 steps just to post the image-i counted