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Preliminary Report for Data Recovery at Site BK -2-062518 Colowyo Coal Company <br />2.3 Sample Collection <br />Heat altered rock recovered within the features was sorted by size class, counted, and weighed <br />per feature in the field as outlined in the HPTP. No other artifacts were observed at the site. <br />All feature fill was collected as bulk feature fill samples for flotation analysis. Radiocarbon samples <br />were collected either directly from the feature or from the recovered fill samples. No additional <br />samples were taken at the site. <br />3.0 FEATURE DATA RECOVERY RESULTS <br />The following is a summary of the investigated features excavated during field work. Descriptions <br />and interpretations presented here are considering preliminary pending further laboratory and <br />post -field work analysis of the collected data. <br />3.1 Feature 1 <br />Feature 1 is the remaining portions of a thermal feature measuring approximately 41 cm north to <br />south by 35 cm east to west (Figure 5). The feature size and location necessitated one 1 by 1 m <br />unit to be established to support the investigation. Actual top of the feature is unknown, but it <br />appears to have been approximately 20 below the modern ground surface. <br />The feature's maximum depth is 23 cm below the 100N 100E unit datum. Overall feature shape <br />appears to be roughly lenticular with an uneven basin shaped bottom. A large, filled in, rodent <br />burrow trends northwest from the feature and has distorted the feature shape in that direction. <br />Feature fill consisted of dark stained sediment (10YR2/1, Black); varying dense charcoal flecking <br />and one piece of heat altered rock. An additional four pieces of HAR were observed in the <br />immediate area at the time of discovery and are considered associated with the feature. Four <br />pieces of heat altered rock are in the 5 to 10 cm diameter size class (0.75 kg) and one piece of <br />heat altered rock is in the > 10 cm size class (0.50 kg). <br />3.2 Feature 2 <br />Feature 2 is a thermal feature measuring approximately 26 cm north to south by 14 cm east to <br />west (Figure 6). The feature profile was exposed 20 cm below modern ground surface in the <br />mechanical cut profile at the Limit of Disturbance line for the Project. The exposure allowed for <br />vertical and horizontal control to be maintained without setting a formal unit. Approximately half, <br />if not more, of the feature was removed by mechanical ground stripping. <br />The feature's depth below modern ground surface is 20 cm. Overall feature shape is amorphous <br />in planview with a shallow lenticular profile. Moderate root and rodent action is significantly <br />distorting the overall shape. Feature fill consisted of dark stained sediment (10YR2/1, Black); <br />sparse charcoal flecking mottled with brown (10YR4/5, Brown) fill with sparse charcoal flecking. <br />The mottled fill may be from either wind blowout post -use but before burial or from significant <br />post -depositional disturbance. <br />Tetra Tech July 2017 <br />