I ran across this CU Resource that I thought people might enjoy:
urango,-La-Plata-Co-,-Col-?sort=city%2Cdate%2Csheet&qvq=w4s:/where%2FDurango;sort:city%2Cdate%2Csheet;lc:UCBOULDERCB1~21~21&mi=28&trs=69" rel="nofollow">Durango, 1898
ilverton,-San-Juan-County,-Colorad?sort=city%2Cdate%2Csheet&qvq=w4s:/where%2FSilverton;sort:city%2Cdate%2Csheet;lc:UCBOULDERCB1~21~21&mi=19&trs=22" rel="nofollow">Silverton, 1910
Central City, 1890
https://cudl.colorado.edu/luna/servlet/browseByCategory
Best Regards,
Nick