Open-File Report 00-145, is a digital geologic map database of the Butler Peak 7.5' quadrangle that includes (1) ARC/INFO (Environmental Systems Research Institute) version 7.2.1 Patch 1 coverages, and associated tables, (2) a Portable Document Format (.pdf) file of the Description of Map Units, Correlation of Map Units chart, and an explanation of symbols used on the map, btlrpk_dcmu.pdf, (3) a Portable Document Format file of this Readme, btlrpk_rme.pdf (the Readme is also included as an ascii file in the data package), and (4) a PostScript plot file of the map, Correlation of Map Units, and Description of Map Units on a single sheet, btlrpk.ps. No paper map is included in the Open-File report, but the PostScript plot file (number 4 above) can be used to produce one. The PostScript plot file generates a map, peripheral text, and diagrams in the editorial format of USGS Geologic Investigation Series (I-series) maps.