Page 96 - Vol. 1 Walks In The Black Range - 2nd Edition

Quartz is the chief gangue mineral. In places the lode consists of a single vein from 2 to 8 feet in width; in others, of a branching system of thin seams occupying a shear zone from 2 to 7 feet wide. These lead out into the country rock on the foot-wall side. The dip is to the west at a high angle- nearly vertical. The ore bodies occur along the walls, here on one side and there on the other. Some distance in from the portal of the tunnel the vein branches, but the branches come together again farther on. At 2,000 feet from the portal of the lower tunnel the vein splits up into several small veins, branching out into the foot walls. At this point the main vein becomes barren, and at the time of visit (1905) crosscutting was in operation in the hope 'of locating the lode’. Mining operations here consist chiefly in drifting on the lode. Some of the upper tunnels extend through the hill and the lowest is about 2,000 feet in length. In 1905 forty men were employed, of whom twenty-five were at work underground. The mill, which had 10 stamps, was found insufficient and has been recently increased to 20 stamps. It began operations December 1, 1904, and up to September, 1905, the net returns on ores from the Bonanza mine were as follows: Bullion, $23,801.51; concentrates, $4,821.02; shipping ore, $7,099.29; total, $35,721.82.”
A Rock Screen, used to separate rock ore by size is still found outside of the mine entrance.
The Bonanza Mine is featured in this video with Steve Elam. (Follow the link - the image below is just an image.)