Describes the evolution of transportation routes and transportation methods in Pima County throughout time, and the effect that modes of transportation have had on the size and form of the community. Stage, freight, and railroad transportation followed the main historic corridors established by previous cultures and technologies.

To facilitate discussion about which species might be considered for protection, a series of in-depth interviews were conducted with members of the local science community who have expertise in the areas of birds, fish, invertebrates, mammals, plants and plant communities, and reptiles and amphibians.