BLM, File - Coal 78 USGS, Casper, WY No description specified. 1-3 (3 Records) Documents BLM Memorandum: Archeological Survey for Coal Drill Hole Ltc-2 (1978) BLM Memorandum: Archeological Survey of Coal Drill Holes (1978) BLM Memorandum: Archeological Survey of Coal Drill Holes (1978)