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east of this location occurred during December, 1993. 'ffiic • station overlies approximately 2100 feet of overburden. The monitoring point established at this site was surveyed DecernbeY' 8, 1993 at elevation 8813.00. Station 98: Station 98 was newly established in 1993 and is located at the (YOSSe-Rhode biu~khouse cabin identified as struct~,ae 34 on permit No. C-81-038; Map No. 9-7. Advance mining of Panel Y in the vicinity of this location ooctu2ed during Decanter, 1993. 'ibis station overlies approximately 2050 feet of overburden. The monitoring point established at this site was surveyed Decanter 8, 1993 at elevation 8758.07. Station 99: Station 99 is located at the Northwest corner of Section 15. The elevation of station 99 was defined by satellite survey in July, 1992 as 7921.9 feet. No mining occurred in the vicinity of station 99 during 1993. Station 99 was resurveyed in January 1994 and showed a 0.96 feet elevation change. it is not apparent whether this elevation change is associated with true movement or the difference in survey techniques. Cover in the vicinity of Station 99 is approximately 1200 feet. Pitkin Mesa Pipeline Subsidence Monitoring Summary Seven subsidence monitoring stations were established at locations along the Pitkin Mesa Pipeline which overlies Panel C. Panel C development cwmnPnced in • October with twenty four crosscuts completed by January 1, 1993. Panel C was completed in April, 1993. Panel C was mined utilizing a partial extraction design intended to preclude the development of subsidence in order to prated the pipeline. 'Ihe subsidence monitoring stations along the pipeline are depicted on Map No. 2-5A, Permit No. C-81-038. The stations were surveyed twice in 1993; May 21 and Oc.-tober 14. Results of both surveys are appendgi to this report. In general, all sites show an elevation gain of approximately 0.2 to 0.3 feet based upon the 1993 survey information. Surveys will continue on an approximately semi-annually until stability is doamiented. Visual Monitoring 1993 Visual subsidence monitoring is accomplished by periodic "walkovers" of recently mined areas within the present permit area. Walkovers are generally done in conjunction with survey monitoring due to the seasonal accessibility of the area. Visual monitoring is concentrated over areas of retreat minim with particular emphasis on areas mined under low overburden. A visual walkover inspection of recerrt.ly pillared areas (Panels A, A+, B, and C) was conducted in conjunction with subsidence and hydrology monitoring in the area during October, 1993. No visual evidence of subsidence was noted in any of these areas. Projected Stabsideace ~apacts 1994 . SUisidence impacts during 1994 are projected to be minimal based upon subsidence patterns established to date. Mining during 1994 is projected to occur in panels Z and 1st North Fast. Development and retreat mining is scheduled to occur in 6