These arcs were smoothed interactively in Arcedit. The coverage then was rebuilt. Attribute items were added to the coverage arc attribute table. These non-interpreted lines were drawn as solid lines on the map. First, contour lines were overlayed with a coverage of outcrop geology for the Madison Formation.
Negative values indicate below sea level.
A value of 9999 indicates that the contour is not a multiple of 500. A value of 'Y' indicates that some interpretation was involved in drawing the contour line. Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials.