Tri-State district
The Tri-State district was a historic lead-zinc mining district located in southwest Missouri, southeast Kansas and northeast Oklahoma. The district produced lead and zinc for over 100 years. Production began in the 1850s and 1860s in the Joplin - Granby area of Jasper and Newton counties of southwest Missouri. Production continued until the closure of the Picher, Oklahoma mines in 1967, and the "Swalley" mine near Baxter Springs, Kansas in 1970.
The tri-state district includes three mining-related Superfund sites: the Tar Creek Superfund site in Oklahoma; the Jasper County and Newton County sites in Missouri; and the Cherokee County site in Kansas.
