"Baker [County] area mines - Platts Group Map" "Platts Group Mining Claims - Preliminary Survey, Amended Locations - Scale 200' = 1 in. - 1904" Includes latitude and longitude directions.
"Baker County [Sumpter, Oregon] area mines, Cracker Creek District - Tramway from North Pole Mines to Mill. Eureka and Excelcior [Excelsior] Mines and Hoist Plant - circa 1901-1903."
"Baker [County] area mines, Sumpter, Oregon - circa 1901-1903 - Copper Mines of the Indiana Mining Company Office Purphyry [periphery?] Dike - Footwall here Ore Vein 400 Ft. wide 20 Ft. Shaft Hoisting Plant Barn Boarding House Hanging Wall Iron Dikeā¦