http://www.sdhistory.org/arc/naturalizationarchives/ naturalization_records.htm Listed thereon will be first papers and second papers along the lefthand side of the page. First papers being declarations and second papers being final certificate papers.  For easy use thereof, click on first papers first, type in the name you are looking for and if it does not come up or there is not a record for that particular person, do the same procedure for second papers. In the event there may be different spellings of the immigrant's name, you may wish to try the various spellings you think apply to that individual.  Once and if you have found your immigrant's name and wish a photocopy of the document, be sure to note the volume and page number thereof and mail a check for $10.60 per copy to:  South Dakota State Historical Society 900 Governors Drive Pierre, SD 57501-2217 Naturalization records after 1906 are also available at the Immigration and Naturalization Service St. Paul District Office, 2901 Metro Drive, Suite 100, Bloomington, MN 55425.