TY  - RPRT
TI  - Map showing structure contours and overburden thickness isopleths of the Pittsburgh coal bed in Pennsylvania, Ohio, West Virginia, and Maryland
AU  - Susan J. Tewalt
AU  - Leslie F. Ruppert
AU  - Linda J. Bragg
AU  - Richard Carlton
AU  - David Brezinski
AU  - Jeanette Yarnell
AU  - Rachel N. Wallack
PY  - 1997
DO  - 10.3133/ofr97864
UR  - https://pubs.usgs.gov/publication/ofr97864
ID  - ofr97864
ER  -