Drilling of the San Andreas Fault under Earthscope's SAFOD has started this summer (2004) and will recover geologic samples that offer unrivaled opportunity to study seismogenic fault rocks and fault mechanics, and relate fault processes to the seismic processes. We propose a two-day mini-workshop to coordinate the research efforts by various scientist teams on core and cuttings samples that will be obtained during the various stages of SAFOD drilling. A small group will convene in Paso Robles, CA on October 8-9, 2004 to discuss research priorities and efforts, as well as make a visit to the nearby drill site at Parkfield where samples are temporarily stored. The workshop conveners are Jim Evans (Utah State), Teng-fong Wong (Stony Brook) and Ben van der Pluijm (Michigan). This workshop will help coordinate research efforts of various groups, identify any gaps in our characterization studies, and begin to develop strategies for integrating the rock characterization efforts with other results from SAFOD, including fluid and gas measurements, borehole geophysical measurements, seismic monitoring, and in-situ stress measurements.