"Development Engineering Inc conducted research and development of the Paraho surface retorting technology under a contract with the Department of the Navy. The work was performed at the Anvil Points Oil Shale Facility near Rifle, Colorado. The shale was mined from the 43 foot high heading, crushed and screened in the mobile crushing units furnished by the Navy and processed in the Paraho Semi-Works retort operated in the internal heated mode. Continuous operations were maintained for 105 days at an average feed rate of 269 tons per day. Mass rate ranged from 410 tp 493 pounds per square foor cross-section per hour. Crude shale oil production ranged from 130 to 170 barrels per day, and shale grade ranged from 21 to 31 gallons per ton."