Jeff Ingram shows the old map he found. (Photo by Pat Blair) A somewhat yellowed map now in the possession of Sheridan resident Jeff Ingram shows sites of some of the old mines and mining communities that once dotted the Tongue River Valley north of Sheridan. Ingram explained how he came into possession of the map. Ingram said he has no idea what year the map was created. Close-up of the undated map. (Photo by Pat Blair) The map shows the sites of Dietz and the Dietz mines, Acme and part of the old Monarch community. There’s also an area colored in red that Ingram speculates might be a mine site that was being looked at or speculated on by whoever created the map.