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..•- ': ~~ <br />---- <br />Cliff Schmid Sur~r~eys <br />PftOFESSIONl1L LLJVD SURVEYORS <br />nEFKE 30}217-Wl~ 777 64w AvE. na 222 <br />HOME 30}3!S_~32! tlmN100, COLO Bi326 <br />tlerch 24, 1987 <br />National King Coal <br />1015 1/2 Mein Ave <br />Durango, Co. 81?~1 <br />Dear Caryl: <br />In 198:, we established 4 subsidenc_ inonitorinq c~~ints o•;er <br />the old workings rn the vicinity of t~,e a~.in ungton Ditch. '1e <br />established these porn*..s with a 5 secona tneo_rte anc alectro nic <br />distance meter for the horiu~ntr.l control. And, an autnmauc <br />level was used to establish the vertical contr=!. The points are <br />monumented by 5/8ths .. 3 tt rebar dr:•:en _ntv the ~-roun~ such <br />that they protrude appror.imaGely ~ or ~ rncaes above tiie cr~=und. <br />Original elevar!ons were: <br />#1 loll !assumed for base <br />#2 106.30 <br />#3 113.01 <br />#4 114.38 <br />These control ports ere examined t~.:ice per annum to check <br />for horizontal and/or vertical changes. -his is accomplished ~~y <br />setting the theolite with EDM over point tt2 back siyht.ng #1 ernd <br />turning the angle to #.3 toth direct ar,d r•~verse. Tt~~e distance <br />Erom #2 to #1 and to #3 are then e!ect:onically measured. The <br />theolite with EDM is tt:en placed over point #; bac:csighting +)2 <br />and turning the angle to ttq ticth fir=.ct and rw arse. The <br />distances to #2 and #4 trom #3 are mien measured. Levels are <br />then run beginning at point #1, going thru points 2 6 ;, and <br />ending at point #4. <br />The data is then compered with [t,e original values. There <br />has been no appreciable difference in nny of the subsequent <br />observations of horizontal angles and/or vertical elevar_ions <br />with the oriainel. The results of each check (that there tied <br />been no movement) is reported (usually verbally) to the King <br />Coal OEFic e. We should Se making another check at the end of <br />April 1987. <br />IE you have any questions, please do not hesitate to ..:a!1 <br />me. <br />Sr:icerely, <br />~'~, ~ <br />t.. , .~ ~ ::. ~ ~ <br />C1iF(ord h. Schmid PLS#11373 <br />