Find Genealogy Records in Thurston County

Thurston County is one of Washington's original counties, formed in 1852, and its genealogy records stretch back further than almost any other county in the state. As the home of Olympia, the state capital, Thurston County benefits from having the Southwest Regional Branch Archives, the Washington State Department of Health, and other major state-level resources all within close reach. Marriage records go back to 1844, court records to 1852, and birth and death registers to 1891. This guide walks through the key sources for Thurston County ancestor research.

Thurston County Vital Records and County Offices

Thurston County was created January 12, 1852 from Clark County, making it one of Washington's founding counties. It was named for Samuel R. Thurston, the Oregon Territory's first delegate to Congress. The Thurston County Courthouse is at 2000 Lakeridge Dr SW, Olympia, WA 98502, phone 360-786-5560. The county auditor holds birth and death records from 1891 to 1907 and marriage records from 1891. The county clerk holds divorce, probate, and court records.

Known beginning dates for Thurston County government records are: Birth 1891, Marriage 1877, Death 1891, Court 1852, Land 1852, Probate 1852, and Census 1850. There is no known history of courthouse disasters, so these early records have largely survived intact. The Thurston County Auditor's Office is at 3000 Pacific Ave SE, Olympia, WA 98501, phone 360-786-5224. Hours are Monday through Friday, 8:00 AM to 4:30 PM (opens at 9 AM the first Wednesday of each month).

Note: The Southwest Regional Branch has three free parking spaces in front of the building; additional parking is available for $1.50 per hour on Level P1 of the nearby Department of Natural Resources lot.

Thurston County Records in the Digital Archives

The Washington State Digital Archives holds a wide range of Thurston County genealogy records. Marriage records are especially deep here. The collection covers multiple series: the 1852 to 1857 Thurston County First Record Book, the 1891 to 1898 and 1970 to 2022 marriage records, and the 1927 to 1950 marriage certificates. These are all searchable with index and images online at no cost.

The Thurston County marriage records collection covers one of the longest date spans of any county marriage collection in the state. The First Record Book entry, dating to 1852, reflects the county's role as one of Washington's original jurisdictions.

Searching by groom or bride name with a year range filter helps narrow results quickly in this large collection.

Beyond marriage records, the Digital Archives holds Thurston County birth registers from 1891 to 1907, death records from the same period, and a substantial naturalization record set. The Thurston County records include 1849 to 1853 and 1906 to 1974 naturalization case files. Probate records from 1853 to 1970 and indexes from 1887 to 1949 were also filmed by the Genealogical Society of Utah and are at FamilySearch.

The Thurston County government website provides current contact information for county offices and departments relevant to genealogy research.

The auditor's office processes requests for historical marriage and land records and can help with documents not yet available online.

Thurston County Land and Property Records

Land records for Thurston County go back to 1852, the year the county was created. The county auditor holds the full range of real property documentation. Online indexes in the Digital Archives include the 1852 to 1857 First Record Book, the 1855 to 2022 Plats and Surveys, the 1900 to 2022 Recorded Land Records, and the 1979 to 2022 Recorded Agreements and Contracts. These land records are particularly useful for tracing family property movement across generations and confirming when an ancestor arrived in the county.

According to RootsWeb Thurston County resources, real property records from 1852 to present are at the Thurston County Auditor's office. Field books including chain of title from 1961 onward are at the Thurston County Assessor's office. Excise affidavits from 1951 and real and personal property tax records from 1977 are at the Thurston County Treasurer's office.

Military discharge records are at the Thurston County Auditor's office, though dates are not fully specified. For estate and probate research, probate records from 1853 to 1970 with indexes from 1887 to 1949 were filmed by the Genealogical Society of Utah. These films cover most of the key genealogy window for Thurston County and are available at FamilySearch locations.

Naturalization and Court Records

Thurston County holds one of the richest naturalization record sets in Washington State. The county was the seat of territorial government, so naturalization proceedings here spanned the full range from early territorial years through the twentieth century. The FamilySearch wiki for Thurston County lists the full set: declarations of intention 1849 to 1974, depositions and interrogatories 1929 to 1941, naturalization case files 1849 to 1907, naturalization correspondence 1907 to 1976, naturalization journals for adults 1891 to 1895 and for minors 1903 to 1906, naturalization stubs and index cards 1850 to 1973, petitions and recommendations 1930 to 1974, and repatriation oaths 1940 to 1964.

These records can be critical for researchers with immigrant ancestors who went through the naturalization process in early Washington. The range from 1849 onward means you can find people who arrived during the territorial period, before Washington even became a state in 1889. The Washington State Archives Southwest Regional Branch holds certificates of naturalization from this period.

For divorce records, 1889 to 1952 Divorce Case Files are at the FamilySearch Library. Divorce records after 1968 are held at the state level through the Washington State Department of Health. For records before 1968, contact the county clerk directly.

Southwest Regional Branch Archives

The Washington State Archives Southwest Regional Branch is located at 1129 Washington Street SE, Olympia, WA 98504. Phone: (360) 753-1684. Email: swbrancharchives@sos.wa.gov. The branch is open for in-person research by appointment, hours 8:30 AM to 4:30 PM Monday through Friday, excluding state holidays.

This branch serves Clark, Cowlitz, Grays Harbor, Lewis, Mason, Pacific, Skamania, Thurston, and Wahkiakum counties. It holds a wide range of local government records including those from county offices such as the Auditor, the Clerk, the Treasurer, the Board of Commissioners, and from municipalities, school districts, and other service districts. There is no charge to request and view public archival documents; fees apply for copies and special research services.

Because the Southwest Branch is physically located in Olympia, Thurston County researchers have an unusual advantage: the state archives are right in the same city as the county offices. All original Thurston County records have been relocated to this branch; the local genealogical society has microfilms of the same information if you prefer to work from that format. Birth and Death Records from 1891 to June 30, 1907 remain at the Thurston County Auditor's office as well. Marriage records from 1844 to present are at the auditor's office.

Cities in Thurston County

Thurston County includes the state capital and several other cities. Genealogy records for residents of these cities run through Thurston County offices and archives.

Nearby Counties

These counties border Thurston County. Ancestors who lived near county lines may have records spread across multiple jurisdictions.