Oil Shale
The Core Research Center collection includes oil shale cores from the Green River Formation in Colorado, Utah and Wyoming.
Anvil Points(Public domain.)
List of all Green River Formation cores in Colorado
List of all Green River Formation cores in Utah
List of all Green River Formation cores in Wyoming
Oil Shale cores are listed as being in the GREEN RIVER Formation.
More information on Oil Shale can be found at:
USGS Energy Resources Program: Oil Shale