History

History of Yankton County

Yankton County played an early and important role in the history of Dakota Territory and the state of South Dakota.

Bordered on the south by the Missouri River, the county is named for the Yankton band of Sioux Indians who lived in the area since the early 1700s. Pierre Dorion was the first non-native person to reside here. Dorion married a Yankton Sioux woman 20 years before the arrival of Lewis and Clark in 1804.

The first known white woman to visit Yankton County was Pelagie LaBarge, traveling on the Missouri River in 1847 on a steamboat piloted by her husband. Major William Lyman was the first known white settler in Yankton County in 1857. Lyman established a ferry across the James River along with a small trading post.

In 1861, the territorial government was established with the City of Yankton designated as the first capital of Dakota Territory. The year 1861 also saw the first official newspaper, β€œThe Weekly Dakotian,” published in Yankton. Steamboat trade flourished here until 1873 when the first railroad line connected Yankton and Sioux City, Iowa.

The first school, held in the home of Dr. Abram Van Osdel, opened in December of 1862. Governor Howard selected Yankton County as the site for the hospital for the insane in September of 1878. Yankton lost the fight to retain the status of Territorial Capital in 1883 when the capital was moved to Bismarck, ND.

The rich history of Yankton County is preserved through many landmark buildings, historical sites and the written word.

Announcements

Yankton County Auditor
Wednesday, September 16, 2026

Absentee voting for the upcoming November 3rd, 2026 General Election will begin on Friday, September 18th 2026 in the Commissioners Chamber Room. Make sure to being a photo ID when you stop by. There will also be sample ballots and reading materials for the amendments available in our office as well

Yankton County Register of Deeds
Monday, September 14, 2026

As of September 14, 2026, the state has implemented a new vital records system. Please expect a delay in all services as we learn and navigate this new software.

September 14th – October 16th you will need to make an appointment to apply for a marriage license. Plan for this to take at least 30 minutes.

Notary services will not be available from September 14th – October 2nd.

Yankton County Treasurer
Tuesday, September 1, 2026

Reminder: Yankton County residents that have last name starting with S, have until September 30, 2026 to renew vehicle registration.

Main Phone:
(605) 260-4400

Address:
321 West 3rd Street, Suite 100 Yankton, SD 57078

Office Hours:
9:00am - 5:00pm CST, Monday-Friday
Closed on Holidays, Saturdays, & Sundays

Yankton County YouTube Channel

Yankton County © 2026. Developed by Intuvio Solutions.