Collection consists of correspondence and legal documents related to James G. Ducey, a mining entrepreneur active in Leadville, Colorado, during the late 19th century. A substantial portion of the collection focuses on Ducey's mining interests associated with the Evans Gulch group of claims in Leadville, including correspondence between Ducey and the other co-owners of the Evans Gulch claims such as James J. Brown, the husband to Margaret "Mollie" Brown of Titanic fame. There is also correspondence between Margaret Brown and Ducey.