Land for sale in Mercer County, North Dakota, recently totaled approximately $6 million and almost 1,000 acres. Mercer County ranks eighth in the Rough Rider State for the combined amount of land currently advertised for sale. Of all land for sale in Mercer County, Hazen had the most land for sale. Mining and mineral extraction-related services are the main economic drivers in this part of North Dakota. Mercer County is North Dakota's 35th biggest county (1,112 square miles). It's located in the Central North Dakota region of North Dakota.