The hand-drawn map does not provide much information with regards to distances. Using the trailhead to Cattail Falls as the starting point, it appears that the distance to Alum Cave is about twice that of the distance to Cattail Falls. I have used Topozone and done some searching there...but no luck thus far. I posted a similar question on the Big Bend Chat Page (
http://www.big.bend.national-park.co...d/bigbchat.htm) but did not get any leads there either...
If nothing else, it is fun to just day-dream about hiking in that area and coming across Alumn Cave or that old mine...