Aspen prepared descriptions of baseline conditions for a study of the Santa Cruz River watershed in Pima County, Arizona, addressing the following topics: wildlife, vegetation, geology, air quality, transportation, recreation, and visual resources. Aspen also prepared a description of the causes of environmental change in the watershed over time. The purpose of the study was to investigate opportunities for watershed management and ecosystem restoration in the watershed. Issues addressed by the plan include river hydrology, river management, habitat restoration, wastewater management, groundwater recharge, stormwater quality, erosion and sedimentation, and recreation.