A combined nearly 1,000 acres were listed for sale in Humboldt County, Iowa, recently; the overall value of all Humboldt County land for sale was $7 million. Humboldt County ranks 85th in the Hawkeye State for the combined amount of land currently advertised for sale. Humboldt had the most land for sale. From an economic perspective, manufacturing and related services are the main sectors in Humboldt County. Humboldt County is the 85th largest county (435 square miles) in Iowa. It's located in the Western Iowa region of the state.