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Cooperation Agreement No. CA 8000 -2 -9001 Work Order No. 8039 -2 -9001 / Within Saguaro National Park only Rincon Mountain District contains significant riparian areas. The geologic framework of the Tanque Verde Ridge and Rincon Valley exerts strong control on the hydrology of these riparian systems. Pantano fault constitutes a line of hydrogeologic separation between the occurrence and utilization of groundwater in the Rincon Valley and the main Tucson basin. No known, comparable fault isolates the upper Tanque Verde Creek alluvium from downstream pumping effects. However, east of the confluence with Agua Caliente Wash, the highly permeable alluvial materials are much thinner, and serve to dampen such downstream effects. Therefore, the ground water reservoirs supporting the riparian areas within Rincon Mountain District are not directly connected to the Tucson basin aquifer. In what is described herein as upper basin areas, high gradient tributary streams to Tanque Verde Creek and Rincon Creek have discontinuous bodies of shallow alluvium interspersed with bedrock channel. Alluvium has accumulated behind small faults or resistant bedrock ledges and contains shallow ground water basins that support small pockets of riparian or xeroriparian vegetation. The ground water in these small basins is sustained by seeps or springs, and by runoff from precipitation and is not likely to be connected to a regional ground water system. In what we have characterized as middle basin areas, the stream gradients are less than 25m/km. In these low gradient reaches, the alluvial floodplain sediments are continuous, though not thick, as ledges of more resistant bedrock formations appear in the stream channel. These low gradient reaches contain larger volumes of ground water than the high gradient basins and support more robust riparian vegetation. The ground water in the low gradient reaches is believed to be connected to the regional ground water system. Such a low gradient reach exists in a tributary to Tanque Verde Creek about 1.4 km east of Wentworth Road and extends about 1.6 km into the Park. A similar low gradient reach occurs along Rincon Creek in the Expansion Area, and at the mouths of Chiminea and Madrona Creeks.

This dissertation traces the history of cattle grazing at Saguaro NP, Organ Pipe Cactus NM and Fort Bowie NHS in southern Arizona. This collection of studies examines the factors affecting that use, the ranchers who made their living from the landscape, and the federal land managers responsible for sustaining the natural and cultural resources. A dominant industry on arid public lands since the Civil War, grazing was altered by a variety of influences: environmental and human-derived. Ranching communities developed from homesteading settlements. Success was determined by climate, topography, and natural resources; social and cultural pressures; economic events and political legislation; and later federal regulations and decisions. The first agency to oversee grazing, USFS was under constant pressure to maximize short-term human benefits. The NPS Organic Act of 1916 mandated conservation of natural resources "by such means as will leave them unimpaired for future generations" and yet approved cattle grazing, an extractive use, under USFS management. Park managers were frustrated by grazing practices not under their control. Parks were at a cultural and social disadvantage. Residents and politicians often expressed displeasure at park reservations; communities feared that parks would interfere with local industries. Park employees supervised visitors and developed recreation infrastructure; they came with little experience to manage livestock. Lack of funding for research, limited manpower, and political and administrative interference allowed cattle grazing to continue unregulated for decades altering vegetation and enhancing erosion. In the 1960s, changing values from the environmental movement, the waning power of the livestock industry, and the rise of activist scientists impelled NPS to act. Without monitoring data, NPS turned to legal opinions to terminate grazing. Now grazing is regulated and carefully monitored. NPS is mandated to incorporate research results into management decisions. Older grazing permits are being retired, but land acquisitions for park additions add new management challenges. Purchasing permits offers a new but financially limited opportunity to protect sensitive lands. Grazing has ended at all three parks, yet ecological changes and historic structures remain. As cultural and administrative legacies, those remnants offer opportunities to interpret a significant regional tradition and an untold controversy.