After doing some research, I did not find anything to put this mine near the North Arrasta Gulch, which I found to be near Silverton, Colorado. The Blanca Mine was nowhere near Silverton, but very close to Alamosa and the Great Sand Dunes, where the Oasis Campground is currently located, so I don't know where the person who put that information into WikiTree.
Blanca Mine is a past producer vein deposit site in the Rocky Mountain System of Colorado, The United States. It is a small deposit, located in the Blanca District mining district and is not considered to be of world-class significance. Gold and lead deposits are documented at "Blanca Mine." Gold is present at a grade sufficient to have a strong effect on the economics of an excavation project. It may even be viable as the only commodity mined. The lead at this site is economically interesting but not currently recoverable. This deposit has operated in the past as a small scale production but was closed at the time it was surveyed. There were no known plans to reopen it. The most important method or feature used in the discovery of economic minerals at this site was ore-mineral in place. Production at this site spanned 1928 -1934.