Riggan supervised this long-term project of calculating and publishing cancer mortality rates and trends for every county in the United States over several decades. The last 30 of the 40 years of the underlying data base includes every death record in the country, not just those which indicate a cancer as a cause of death. This data remains valuable for researching the relationships between exposure to environmental factors and causes of death. Digital facsimile from the Hathi Trust at this link.