This investigation was undertaken to study the product distribution upon catalytic cracking the coker distillate from crude Colorado shale oil. The crude shale oil processed was produced in a 150-300 ton per day experimental Gas-Combustion retort by the Bureau of Mines Oil Shale Mine and Engineering Experimental Station, Rifle, Colorado. The crude shale oil was coked for the production of distillates having 650, 750 850 degrees F. end points and sent to Tide Water Associated for catalytic cracking tests. Letter on the above over Mr. R. J. Cameron's signature was dated December 9, 1953.