https://books.google.com/books?id=v3LOAAAAMAAJ&pg=RA2-PA327&lpg=RA2-PA327&dq=napa+county+%22iron+mine%22&source=bl&ots=kLzO_aiO8k&sig=ACfU3U0jN2sYhbapUBvNpvSzL5gtseMpjg&hl=en&sa=X&ved=2ahUKEwizirOb84H1AhV2GjQIHZGMDkQ4WhDoAXoECCAQAw#v=onepage&q=napa%20county%20%22iron%20mine%22&f=false