The Office of Surface Mining in Knoxville, Tennessee funded the production of digital replicas of USGS 7.5-minute series topographic quadrangle maps covering the coalfield of Tennessee. These digital replicas are in AutoCAD 14 (.dwg) drawing file format and represent the latest revision of each standard 7.5-minute quadrangle map at the time of conversion. 

The original data was produced either by the USGS or the TVA as a hardcopy map. The drawing files were made by scanning stable base color separates obtained either from USGS or TVA. The color separates were either software vectorized or manually "heads up digitized" from the scanned images. The vector data was then converted to Tennessee State Plane, NAD 27 coordinate system. These replicas inherit all errors and inaccuracies present in the original data.

For more information about these files, contact Bill Card, Office of Surface Mining, 710 Locust Street, Second Floor, Knoxville, Tennessee, 37902, tel: 865.545.4103, x. 134, e-mail: bcard@osmre.gov.