Spurred on by the persistent efforts of John Rapp (now at Logan Simpson Design, Inc.) in 2000-2001, we initially analyzed samples from a sizeable number of Phoenix Basin FGV sources so as to evaluate their efficacy for geochemical provenance studies. While there were some clear distinctions among the different regional toolstone sources, the degree of compositional overlap was sufficient enough to make reliable source identification difficult and we eventually discontinued our studies in the area (we'll eventually summarize the results of this research through this web page). Later on, while working on trace element studies of Flagstaff area obsidian and FGV sources with Ted Roberts (then a graduate student at Northern Arizona University), we added the Presley Wash and Black Tank sources to our list of useful FGV sources.