The great Quincy is perhaps one of the best known mines of the area.  Originally created in March, 1848, it mined the area north of Hancock for almost 100 years.  It's ability to make profit and generate dividends earned it the nickname of "Old Reliable".
So much has been written about the company that it would be fruitless for me to try here.  Perhaps the best reference on the company is the book "Old Reliable" by Lankton and Hyde, published 1982.

Below are a couple of miner's brass tags from the Quincy.