Present in Michigan County: Dow Chemical Co. In Midland and Mason Counties, Michigan Chemical Corp. in Gratiot County, Morton Salt Co. and Standard Lime & Stone Co. in Manistee County.; Geological Formation: Filer Sandstone Sylvania Fm.; Specific Mine Name: 1927-present; Commercial Mining History: 1927-present; Published Literature: Egleson, G.C. and Querio, C.W.,1969, Variation in the Composition of Brine from the Sylvania Formation near Midland, Michigan, Current Research, Vol. 3, No. 4, p. 367-371; Unpublished Literature: ; Comments: Michigan's Annual Statistical summaries list Mg production; USGS Critical Mineral Reference:
