Delmont lies just off US 18 in
Douglas County, on the edge of the Yankton Indian Reservation, in the
Dakota Heritage & Lakes Region.
Delmont had the same beginning as did probably most of the towns in South Dakota: the railroad. Because of that railroad, places for marketing and purchasing of supplies were needed. And this is the beginning.
The Onion House is listed on the Register of Historic Places. This building is significant because of its architectural design, particularly in a small town in an agricultural area. According to Douglas County tax records, this structure was built in 1902 by the owner Thomas Lenehan.
Mr. Lenehan built his home with a Russian style metallic dome in a community of mostly German-Russian heritage. There were no major exterior alterations ever done, although there were some on the interior. While it has changed ownership before, it is now back in the family, owned by Verla Lehman.
