Coal has been mined in Washington since 1853. Although current production is from surface mines, nearly all coal produced prior to about 1970 came from underground workings. Since early in this century, Washington State law has required mine operators to submit detailed plans of all underground coal operations to the state on an annual basis. About 1,100 individual maps representing about 230 mines comprise the Washington State coal mine map collection, which is held at the Washington Division of Geology and Earth Resources. The maps are an invaluable source of information for mine subsidence hazard evaluation and mitigation, structural geology, coal exploration, resource evaluation, and historical research.
A catalog, index, and user's guide for the collection has been published by the Washington Division of Geology and Earth Resources as Open File Report 94-7:
- Schasse, Henry W.; Koler, M. Lorraine; Eberle, Nancy A.; Christie, Rebecca A., 1994, The Washington State coal mine map collection--A catalog, index, and user's guide: Washington Division of Geology and Earth Resources Open File Report 94-7, 109 p.
The Washington State Coal Mine Map Collection has been scanned and is available electronically.
Maps less than 52” wide were scanned using a wide-format roller feed scanner. Larger maps were scanned in sections on a flatbed scanner and digitally reassembled. Maps were originally scanned as grayscale TIFF images at a resolution of 400 ppi or less to manage file size. The collection was converted JPEG to further reduce file sizes and produce images that could be easily downloaded and managed by the user.
Coal mine maps are organized by county and packaged into 65 zip files, each of 200 MB or less. Map titles are derived from the index numbers used in the catalog (Open File Report 94-7). Use the catalog to determine which maps are of interest. The alphanumeric map index number begins with an alphabetic abbreviation for the county, followed by a numeric mine identifier and an alphabetic map identifier. For example, the index number K59_C identifies the third map in a series, for the 59th mine listed in King County in the map catalog.