- Parent County: Dewey County was created 8 January 1873 from unorganized territory.
- County seat: Timber Lake 
- Interactive Formation Boundary Map of North Dakota - shows boundary changes for South Dakota Counties
- South Dakota Historical Boundary Changes - list of all boundary changes by county provided by Newberry Library
The following are locations in the county
A major portion of the Cheyenne River Indian Reservation is located in Dewey County. The remainder of the reservation is in Ziebach County.
Business, Commerce, and Occupations
| Historical populations
State Census Records
Federal Census Records
Federal Censuses were taken for South Dakota starting in 1910. For links to Federal census indexes, see South Dakota Census.
Church records vary significantly depending on the denomination and the record keeper. They may contain information about members of the congregation, such as age, date of baptism, christening, or birth; marriage information and maiden names; and death date. For general information about South Dakota denominations, view the South Dakota Church Records wiki page.
Emigration and Immigration
Ethnic, Political, and Religious Groups
Land and Property Records
Land and property records can place an ancestor in a particular location, provide economic information, and reveal family relationships. Land records include: deeds, abstracts and indexes, mortgages, leases, grants and land patents.
See South Dakota Land and Property for additional information about early South Dakota land grants. After land was transferred to private ownership, subsequent transactions were usually recorded at the county courthouse, where records are currently housed.
Online Land Records
Local histories are available for Dewey County, South Dakota Genealogy. County and town histories may include biographies, church, school and government history, and military information. For more information about local histories, see the wiki page section South Dakota Local Histories.
Maps and Gazetteers
World War I
Naturalization and Citizenship
South Dakota Newspapers Online
South Dakota Newspaper Catalogs
- U.S. Newspaper Directory, 1690-Present on Chronicling America - contains a list of all known newspapers and the dates they cover; once you locate a newspaper name, contact the local library to see if they have copies of the newspaper.
Additional newspapers abstracts can sometimes be found using search phrases such as Dewey County, South Dakota Genealogy newspapers in online catalogs like:
In most counties in South Dakota, probate records have been kept by the county judge. They include wills, fee books, claim registers, legacy records, inheritance records, probate ticklers, and dockets. The records are available at the county courthouse.
The FamilySearch Catalog lists films of probate records. To find the records for this county, use the Place Search for South Dakota, Dewey then click Probate records.
South Dakota tax records complement land records and can be used to supplement the years between censuses. There may be gaps of several years in the records.
Vital Records consist of births, adoptions, marriages, divorces, and deaths recorded on registers, certificates, and documents. See the CDC Where to Write website for information on acquiring copies of these records.
Family History Centers
Family History Centers provide one-on-one assistance and free access to premium genealogical websites. In addition, many centers have free how-to genealogy classes.
Timber Lake & Area Historical Society
PO Box 181
Timber Lake, SD 57656
Telephone: 605-865-3553, 865-3546, or 1-800-664-3546
Cheyenne River Sioux Reservation
- ↑ 1.0 1.1 The Handybook for Genealogists: United States of America,10th ed. (Draper, UT:Everton Publishers, 2002).
- ↑ https://en.wikipedia.org/wiki/Dewey_County,_South_Dakota accessed 1/31/2017
- ↑ http://genealogytrails.com/sdak/dewey/ accessed 1/31/2017
- ↑ The Handybook for Genealogists : United States of America, 10th ed., (Draper, UT: Everton Publishers, 2002)Dewey County, South Dakota, p.624
- ↑ Wikipedia contributors, "Dewey County, South Dakota," in Wikipedia: the Free Encyclopedia,https://en.wikipedia.org/wiki/Dewey_County%2C_South_Dakota accessed 3 November 2016.