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Preliminary Report for Data Recovery at Site BK -2-062518 Colowyo Coal Company <br />Table 1. Recovered Feature <br />Feature No. <br />Description <br />Associated Unit <br />F1 <br />Semi -circular thermal feature <br />10ON 100E <br />measuring 41 by 35 cm. <br />F2 <br />Amorphous thermal feature <br />N/A <br />measuring 26 by 14 cm. <br />2.2 Evaluative Testing <br />Tetra Tech conducted evaluative testing within the intact sediments that are still present to the <br />west of Feature 1. The evaluative testing was completed using shovel probe testing (STP). STPs <br />were oriented in parallel rows with individual probes spaced 5 m (16 ft) apart. The two rows were <br />spaced at 4 m (13 ft) apart. STPs were 30 cm in diameter hand dug holes excavated using a <br />spade shovel. Excavation was conducted in 10 centimeter (cm) arbitrary levels below ground <br />surface. All excavated sediment was sifted through 1/4 inch wire mesh screen. <br />Four STPs were completed within the intact sediments south of identified Feature 1. STP rows <br />Al to A2 and B1 to B2 were completed within the Project's Limit of Disturbance. The encountered <br />sediment remained consistent throughout the entire depth of all four STPs. No stratigraphic <br />changes were observed in the completed STPs. The sediment is a brown (10YR5/4) compact silt <br />clay loam. Gravels varied significantly; however not consistently enough to suggest stratigraphic <br />or any other sedimentary structure. None of the completed STP's encountered cultural material <br />and/or evidence of a buried A Horizon. <br />Based on the testing results, the horizontal extent of the site appears to be limited to the <br />immediate areas around each exposed feature. No evidence of the cultural component being <br />deeper than what has already been exposed was observed. The potential for additional <br />subsurface cultural material to be present at the locality is low. <br />Tetra Tech July 2017 2 <br />