> -----Original Message----- > On Behalf Of Erika Meyer > > Hugh wrote: > >Could you point me to some reading on this topic? I'd appreciate it. > > This will give you an idea of the level of diversity in California: > http://www.epa.gov/region09/air/maps/r9_tribe.html <snip> Thanks, Erika. I wanted to acknowledge your email ASAP. I'll be reading a lot in the next day or so. Thanks, -- Hugh