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. Government. Attribute accuracy is tested by manually comparing hard-copy plots of the digital data with the source materials. The author 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 most ground locations were plotted manually without aid of GPS, surveying or other precise locating equipment. As with all things human, potential exists for error in location by the mapper in the field especially as many ground locations were plotted manually without the aid of GPS, surveying, or other precision locating equipment. Other vertical positions derived from the plotted horizontal position on the topographic base. The map data was inked onto a stable-base USGS 7.5 minute topographic map. The map was scanned using Anatech Scansmith software driving an Eagle 4080 ET scanner to produce .tiff files.