----------------------------Original message---------------------------- Re geologic mapping of California: there is almost an embarrasse de richesse when it comes to indexes to look up what mapping is available. The classic is the USGS Geologic Map Index of California - the last I knew, it was available free of charge from USGS Distribution in Denver. The California Division of Mines and Geology has published numbers in the Special Reports series that are geologic map indexes. And Joe Crotts at Cal State Univ/Chico has an index by quad name, in digital form; early versions of this were published in the Information Bulletin of the Western Association of Map Libraries. Other responses to your request may give specific addresses, etc. - I'm in another office at the moment - if they don't, send a message to me directly and I'll provide you with specifics. Mary L. Larsgaard, Map & Imagery Lab, Library, UCSB [log in to unmask]