SCALE 1:250,000 CONTOUR INTERVAL 200 FEET Geology mapped principally from 1991-2000 by RFD, M.RV, E.JV, H. LG , and C.LT Editing and layout by R.F. Diffendal, Jr. and D. Ebbeka Map production by J. Nothwehr and L. Howard Revised slightly 6 January 2009, 20 July 2010, 5 October 2010, 10 September 2012.