Montana Oil And Mining Journal

HARDROCK MINERS TAKE FINN E REGION

Jefferson Gulch, near Finn, Montana, an old time producer which yielded heavily of the yellow metal back in the '60's and '70's and has long been relegated to the list of placer diggings which could no longer be profitably worked with sluicing, is staging a comeback in the field of quartz operations. Comparatively little placer ground remains to be worked, but the hard rock men are finding abundant indications of fine ore and old Jefferson bids fair to become one of the high spots in Montana mine developments.

There is marked resemblance between the geological structure of the Marysville district and that of Jefferson which is probably an extension of the Boulder batholith. The mineral veins are, for the most part, of the epithermal and mesothermal type and occur in a small stock of quartz monzonite roughly parallel with the surface contacts of the Newland formation which consists of dolomitic limestone and calcareous argillite.

Surface conditions indicate a smaller area of erosion that of the Marysville country. Old time rock men, following the flat lead theory, drove their tunnels at the point where the float or surface ore stopped and as a result found that the leads pinched out in a short distance. Modern operators are taking advantage of the findings of the old timers and are running their tunnels lower down. Findings within the last year indicate that some interesting deposits will be uncovered in the near future.