This week a Newman Portal user searched for the term "Black Bess." Newman Portal identifies but a single useful source, the 1882 Annual Report of the Director of the Mint Upon the Production ofPrecious Metals. "Black Bess" refers to a mine in Roop County, NV, in the northwestern part of that state. The Report states of this area

Of the Black Bess specifically it reports

Mine names of the era are similar to those of modern thoroughbreds - chosen for good luck or distinction, or simply at the whim of the owner. Others include "Tam O'Shanter," "Silver Wave," "LittleEmma," etc.

Image: extract from the 1882 Annual Report of the Director of the Mint Upon the Production of Precious Metals

Link to Annual Reports....upon the Production of Precious Metals (1880-1909) on Newman Portal:
https://nnp.wustl.edu/library/publisherdetail/510307