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1988 PRODUCTION AND GEOLOGIC CONDITIONS J Cyprus Orchard Valley Coal Corporation (COVCC), in conjunction with Colorado Westmoreland Inc., produced approximately 420,000 tons of coal from the Orchard Valley West Mine in 1988 from Federal Coal Lease IIC-37210. Colorado Westmore- land Inc, experienced a similar production rate in 1987. The 1988 production was for an eleven month period as was 1987. However, the first 4 months of pro- duction during 1988 was on a single shift per day basis with a 4 day work week of actual production. After marketing requirements increased the need for coal, production went to two shifts per day for the remainder of the year. Mining at the Orchard Valley West Mine during 1988 consisted of both advance mining and pillar retreat extraction. The advance development consisted of Fin- ishing the Second West Submains during the first quarter of 1988 and then ad- vancing Panel G northward from the Second West Submains. Retreat mining by partial pillar extractions was started in Panel G after completing advancement. The geologic and mining conditions observed varied somewhat between the second West Submains and Panel G. Differences were primarily influenced by seam thick- ness, interburden thickness, local lithology, and some minor encounters of water. A concise description of the conditions encountered in each section is swnmarized as follows: Second West Submains • Mined length: Submain type development was advanced east for 800 feet. (1132-Ik38 crosscuts) Overburden thickness: 500-650 ft. Mining height : 9-11 ft . Roof: Comprised of mud stones with a high concentration of pots and slick- enslides throughout the remainder of the section. Top coal of 4-5 fee[ in thickness was left to prevent roof problems that would normally be encountered with this strata type. Ribs: Moderate rib sloughage occurred in local areas. This varied due to mining height and some local areas of loosely cleated coal. Floor: The Lower "D" coal seam was used as floor which provided competent conditions. Anomalous conditions: Water seepage was sporadic with minimal flow, which created minimal problems. Panel G Mined length; 3900 ft. of advancement and pillar extraction started. • Overburden thickness: 400-950 ft.