With the passage of the Federal Endangered Species Act in 1973, the stage was set for a confrontation between urban development and the provisions of Federal Law. Language was amended to the Act that established standards that a plan would have to meet before the Fish and Wildlife Service could approve it and issue a permit for the take of a listed species. In those jurisdictions that have adopted this approach, conservation of natural resources is no longer an afterthought but a major element that has to be considered during the regular land use permitting process.

Arizonans have been divided in their feelings about growth and what to do about it, especially during the past two decades. To complicate matters, the debate over the best responses to growth has been drawn along overly simplistic lines—the economy versus the environment. Arizonans who follow the myriad issues related to urban growth closely are becoming convinced that the discussion needs to be recast in a new light.

Scholar Leo Marx coined the phrase “the machine in the garden” in 1964 to describe the relationship between nature and technology. Considering much of the writing about Arizona’s growth, it seemed an apt title for this volume of Arizona Policy Choices. "The Machine in the Garden" presents growth policy choices for Arizona along a continuum: Yesterday’s Growth—the policies that have been used in the past; Today’s Growth—the “smarter” approaches from around the country; and Tomorrow’s Growth—cutting edge thinking about the economy and experiments in urbanism and governance.