Land for sale in Day County, South Dakota, recently totaled nearly $11 million and approximately 2,000 acres. Day County ranks 19th in the state for the combined amount of land currently advertised for sale. Webster featured the most land for sale. Agriculture and farming drives the Day County economy, with 693 farms recorded in the county during the U.S. Census in 2012. Farming activities in Day County generate annual revenues of $9 million, most of which is from crops. Day County is the 28th biggest county (1,091 square miles) in South Dakota. It's located in the Glacial Lakes & Prairies South Dakota region of South Dakota.