Nederland Area Historic Society
www.nederlandmuseums.org

Denver Public Library
history.denverlibrary.org

Western Museum of Mining & Industry
www.wmmi.org

Boulder Public Library Carnegie Branch
boulderlibrary.org/carnegie

Colorado Historic Society
www.coloradohistory.org

Mining Artifacts and History
miningartifacts.homestead.com/index.html

National Mining Hall of Fame and Museum
www.leadville.com/miningmuseum