See readme.txt file for explanation of organization. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Govenment. Attribute accuracy was tested by manually comparing hard copy plots of the digital data with the source materials. Authors as well as USGS map editors performed separate reviews. Polygon coverages were queried to screen for empty or inconsistent values.
Line geometry is topologically clean.
As with all things human, potential exists for error in location by the mapper in the field especially as all ground locations were plotted manually without aid of GPS, surveying, or other precision locating equipment. As with all things human, potential exists for error in location by the mapper in the field especially as all ground locations were plotted manually without aid of GPS, surveying, or other precision locating equipment. Most vertical positions are derived from the plotted horizontal position on the topographic base. The original map data was manually transferred to separate stable media overlays registered to a stable-base USGS 7.5 minute topographic map. The overlays were scanned using Anatech Scansmith sofware driving an Eagle 4080 ET scanner to produce .tiff files.