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<br />COLO. TECH. CENTER <br />CONT'D <br /> <br />a stream or gully, these stand out much <br />better on the low light angles. Then the <br />infra red shows contrast in soil types as <br />related to moisture; so, you get a much <br />better definition of what the features are <br />on the ground. On this particular project <br />we had this low light angle, infra red <br />photography both printed in false color in <br />order to be able to study this area and to <br />see that there are many features that we <br />could identify that would be related to the <br />subsidence hazards. From this photography <br />and with survey patrol, established by a <br />registered surveyor and standard practices, <br />we had this topographic map prepared. <br />This map gives us the surface, and we know <br />exactly what the configuration of the surface <br />is. All the houses, the lakes, all the <br />agricultural features, the differences in <br />elevation are shown on this map. Then we <br />asked the surveyor to take the mine maps. <br />Now we went to the state to the Bureau of <br />Mines and to our own files, which we have <br />obtained maps from the Colorado Fuel Co. <br />We obtained the latest map on file at the <br />State Bureau of Mines office. Every mine <br />in colorado requires they file a map with the <br />State Bureau of Mines, and we have obtained <br />the latest map file and in each case these <br />were the maps that were filed after the <br />closing of the mines. These maps were <br />prepared by a registered surveyor and filed <br />with the State. We took those maps and <br />turned them over to our surveyor and we told <br />him to go out and we want you to survey in <br />all of the identifiable features which we <br />can use to correlate the mine map with the <br />survey map that you prepare. This would in- <br />clude such things as the shafts, the air <br />shafts or the inclines. He surveyed in all <br />the section parts and you will notice we have <br />mine shafts that are well beyond the limits <br />of the CTC. We have these surveyed in. <br />Then, taking the survey points on the surface, <br />the points on my maps, we compiled this map <br />which shows the details of the mine workings. <br />The surveyed mine maps as filed with the State <br />Bureau of Mines are superimposed on our <br />topographic map. Now there has always been <br />some question, and I have heard it many times, <br />that these mine maps are not accurate. But, <br />in our drilling over the last five years, we <br />have never established the fact that a single <br />map was inaccurate. <br /> <br />-7- <br />