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saturating only partially the aquifers along the way. • Drill holes were, without exception, very dry in passing through the Cliffhouse sandstone-siltstone which overlies the Menefee. Cliffhouse surface waters apparently do not migrate vertically and contribute to the ground waters of the Menefee. Omitted from this discussion is the contribution from Coal Gulch and its tributary gullies where the Menefee is exposed by erosion. This contribution would be offset in some degree by seepages from the updip exposures of the Menefee. An appropriate stratigraphic reference for ground water hydrology in the area shown in Map A might be the top of the Point Look- out, or the Menefee-Point Lookout contact surface. Most deep domestic wells in the area bottom in the Point Lookout. It is about 150 feet thick, is of fairly uniform texture and composition, and is underlain by the impervious mancos shale. This formation would seem from these characteristics to be a more uniformly saturable formation, hence have a more reliable piezometric surface for reference purposes. Elevation contours have been drawn on Map A to indicate the depth of the Menefee-Point Lookout contact surface. From the contours, dips of 2~-17% to the south and southeast have been inferred in the northern and western parts of the area of Map A. The blue arrows are gradient vectors, indicating the direction and maximum dip of the contact surface and, • reasonably, the most probable direction of ground water flow in or near that surface. The ground water domain of interest here lies north and southwest of the access of the Durango anticline and as previously stated, is bounded on the north by the outcropping belt of Menefee and Point Lookout strata exposed 200-400 feet about Lightner Creek. In this domain, ground water flowing along, or in the vicinity of referenced surface, would be in a southerly direction. Eventually, most of the ground waters of this domain come under the influence of the perine peak syncline and Durango anticline. As shown on Map A, these structures are nearly parallel over a considerable distance. The anticline is about 100 feet higher across the section than the trough of the syncline, and acts as a barrier, slowing, then diverting the ground water flow to the south- west along the access of the syncline. The trough of the syncline with this low angle of pitch has some characteristics of an underground basin. The ground waters of the domain - from the northeast in the area of applicant's coal lands, from the north, from the northwest and the Hesperus area - are all squeezed into the trough region, creating a region of higher saturation than exists in any of the tributary areas. The impact of sight development, underground mining - 7 -