Geology and Mineral Resources of Douglas County, Oregon – by Len Ramp – Originally published as Bulletin 75 by the Oregon Department of Geology and Mineral Resources, this publication is now back in print by Sylvanite, Inc. A great resource on all the mines and districts both placer and lode from Douglas County, Oregon. This County was exceptionally rich in Minerals and new deposits are still being discovered today. Covers all known metals in the county but this county was particularly well known for its Gold Deposits, and a majority of this book covers that, but other minerals such as Copper, Nickel, Silver, Chromite to name a few are also covered. Non Metallic mineral are also covered such as Aggregates, Clays, Coal, and Gemstones also covered.