The database Georef shows a fair amount of material on Hermosillo before 1970. The earliest record I saw was from 1900. Pam Enrici Engineering, Science, and Geography librarian Univ. of MN., Duluth (on the shores of Lake Superior) On Wed, Jul 15, 2015 at 10:58 AM, Mark Walker <[log in to unmask]> wrote: > Dear Friends, > > I received an inquiry today from a engineer doing an environmental study > around Hermosillo. He is looking for pre 1970s information " any historical > topographic maps, geologic maps, aerial photographs, or land use maps for > the Hermosillo area with a scale around 1:50,000.” > > I can’t find anything older than 1975. Any ideas if anything exists prior > to 1975? > > > Mark Walker > World Map Source / Mexico Maps > 3920 Maricopa Drive > Santa Barbara CA 93110-1414 > 805-448-7273 mobile > 805-687-1011 office >