Concern has been expressed that mesquite bosques are disappearing or diminishing in quality, and that the survival of the mesquite mouse is consequently threatened. This study, funded by a grant from the Arizona Heritage Fund to the Pima County Regional Flood Control District, investigated the current distribution of the mesquite mouse by reviewing historical records from museum specimens, examining existing potential habitat at historic locations of the species and elsewhere in the county, and conducting a live-trapping study at 19 sites representing a range of ecological communities with mesquite as a major component.

A number of significant positive and negative economic impacts could result from Pima County's SDCP and related programs, according to an analysis of existing research on large-scale conservation planning undertaken to provide a framework for community decision-making. This report offers no final verdict on the net economic impact of Pima County's current, ambitious initiatives in habitat conservation and growth management. However, it does provide a framework for future assessment and decision-making.