It is believed the first missionary to SD was Father Pierre Jean DeSmet, a Belgian-born Jesuit, who ascended the Missouri River in the spring of 1839 on a steamboat appropriately named the St. Peter. On May 11 he debarked near the mouth of the Vermillion River where he began a missionary career until his death in 1873. The Yanktons were fascinated by him and his message. He offered Mass which impressed the spirtually conscious Indians during those years. Other Catholic priests to enter SD were Father Hoecken approx. 1840 at Fort Pierre, Port Lookout, the "Village of the Yanktons and Augustine Ravoux. Some historians have credited Jedediah Smith, the Bible-carrying Methodist frontiersman with delivering the first public prayer by a non-Indian in SD aboard the steamboat Yellowstone in 1823. It was 17 years later before the first Protestant minister, Rev. Stephen Return Riggs, a Presbyterian, visited Fort Pierre and conducted services.
Source: Challenge, The South Dakota Story, by Robert F. Karolevitz. Although I don't find a PUTNAM in the index this is an excellent book on the early history of SD and would add much to your family history. You might be able to order the book through "Interlibrary Loan"...Andie Sindt, SD