A History of Working Landscapes: The Altar Valley, Arizona, USA

Approaching rangelands as working landscapes begins from the premise that people and the environment shape each other over time. Sustainable management is therefore not only an ecological but also a social process, strongly infl uenced by local histories of resource use, management, change, and learning. The case of the Altar Valley, Arizona, offers insights into how economics, range science, mental models, and the scale of decision making have shaped ranchers and the landscape over time. In particular, it provides empirical answers to important questions facing range science today: How do scientifi c knowledge and recommendations affect on-the-ground management? How do ranchers weigh economic, ecological, and cultural goals against one another? What kinds of information do ranchers and other parties need to solve problems and improve stewardship in a rapidly changing West? The Altar Valley is an approximately 618,000 acre (250,000 hectare) watershed located just north of the United States‐Mexico boundary and east of the Tohono O’odham (formerly Papago) Indian Reservation. Elevations range from around 2,460 to 7,710 ft (750 to 2,350 m), and average annual precipitation grades from 8 to 24 inches (200 to 600 mm) with elevation (Fig. 1). Landownership is a mosaic of state trust (47.5%) and private lands (11.3%) in most of the center of the valley, with areas of US Forest Service (11.9%) and Bureau of Land Management lands (2.3%) concentrated in the surrounding mountains. The Buenos Aires National Wildlife Refuge (NWR) comprises a large block of land (18.8%) in the southern end of the watershed; portions of the Indian Reservation comprise the rest (8.3%). Thirteen large properties (12 ranches and the Buenos Aires National Wildlife Refuge—which was formed from a ranch in 1985) control 80 percent of the land base in the watershed. The refuge is not grazed by livestock; one ranch is a dude ranch, grazed by horses; the remaining ranches all run cattle. The ranches contain approximately 66% of the valley’s private land. Although relatively overlooked by scientists, agencies, and environmentalists during the 20th century, the Altar Valley has recently emerged as a focal point in the politics of conservation in Pima County, Arizona. Despite dramatic changes in the structure and composition of vegetation and in watershed function (see below), the area provides habitat to numerous listed threatened or endangered species. Compared to the rest of eastern Pima County, the Altar Valley is also remarkably unfragmented by residential development, although the fringes of metropolitan Tucson (population approximately 1 million) reach right up to its northeastern edge. In consequence, advocates of wildlife and open space conservation are increasingly interested in the activities of the families who own the valley’s major ranches. With market prices for private land in the valley ranging upward from $3,000/acre ($7,410/ha), the incentive to subdivide and the equity values of these ranches are both very high. Recently, Pima County purchased one of the ranches for open space protection and leased it back to the previous owners to manage.