Description |
A large part of the early development work on most mining properties consists of surface excavations, such as open cuts, trenches, shallow shafts, and short tunnels. Of this work the greater proportion maybe classed as the annual labor performed on unpatented claims. This assessment work entails the expenditure of large sums each year throughout the mining regions of the West. The unit cost of this work, of course, varies greatly under the peculiar conditions applicable to particular localities. There is, however, a much greater difference in the cost of mining work in separated regions as depth is reached. |