The 1906-D Barber half dollar was struck in 90% fine silver at the Denver Mint, during that facility's first year of operation. The Denver plant was opened in 1906 to serve the fast-growing coinage needs of the western plains and Rocky Mountain regions. Located at the junction of several major railroad lines, Denver was in transformation from a cattle town to a major western city. The 1906-D Barber half dollar is prized by collectors as a first-year-of-operation Denver Mint issue.