5MT18632

True north (14 degrees declination) USGS Quadrangle Map: Mud Creek, Colorado, 7.5 minute, 1979.

Two datums (large nails) were set in at the site to establish a mapping grid. The primary datum for the site was assigned an arbitrary designation as 400N 400E and 100 m of elevation. This datum was marked as ﾑDatum 1ﾒ with a foil tag tied around the nail. True north was defined for the grid by using a hand compass and an easterly declination of 9 degrees, and approximately 53 seconds (given the limitations of a hand held compass this was the precision available). This was the declination suggested by the National Oceanic and Atmospheric Administration website on August 31, 2015 (geomag.models@noaa.gove), for Cortez, Colorado. Ideally, high precision GPS readings on the primary datum, and subsequent datums, should be taken to correct for any variance from true north creating during grid set-up.

A Topcon GT-303 electronic total station, and a Topcon FC-250 data collector were used to map the site and collect 153 individual data points. Coffey operated the total station and adult participants held the prism rod that served to mark the points collected. Coffey also kept a written log of points collected, and details about the height of the rod and the total station (which are also included in the digital data). Those records are on file at Crow Canyon. Backsighting, or shooting to a known point from a set-up location, was done at several intervals during the mapping process. No obvious errors or discrepancies were noted in the data during this backsight process, or in subsequent data processing.

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A well-defined roomblock (framed by upright slabs), a possible pitstructure depression, a midden, several extramural features, and an artifact scatter are visible at the modern ground surface.

None; all artifact analysis was done in the field with no collection.

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A two-track road runs through the western part of the site.

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Modern ground surface.

Not applicable.

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An in field analysis of a sample of artifacts was completed via nine, 3m-radius dogleash tally units.