Sacred Cows at the Public Trough by Denzel and Nancy Ferguson, Maverick Publication (1983) trade paperback, 250 pages, ISBN 0892880910 is a diatribe targeted at excessive grazing of cattle on the public lands of the western United States. It contains a number of assertions regarding the effects of overgrazing on ecology and the environment.
One assertion, on pages 64 and 65, is that overgrazing may result in substantial erosion and the deposit of substantial sediment into streams. The Rio Puerco Basin, which is deeply incised with arroyos, is cited as an example. Rio Puerco delivers 78% of the total suspended sediment load of the Rio Grande although it drains only 26% of the Rio Grande Basin and provides only 4% of the runoff. Research shows cyclic arroyo creation and filling in the basin, and that the current period of arroyo creation begin in the late 1800s in the lower reaches, then moved upstream, but that sediment is now decreasing. The cited period of arroyo cutting in the Southwest, 1865 to 1915, roughly coincides with the period of open range grazing. One alternative explanation is climate change with resulted in heavy rains.
Another assertion, from page 73, is that grazing greatly impacts the riparian zones of streams. Cattle congregate in riparian zone and graze them intensely.
- Rio Puerco On-Line USGS
- "The Rio Puerco Arroyo Cycle and the History of Landscape Changes" Scott Aby, U.S. Geological Survey, Albuquerque, New Mexico; Allen Gellis, U.S. Geological Survey, Albuquerque, New Mexico; and Milan Pavich, U.S. Geological Survey, Reston, Virginia
- "Erosion in the Rio Puerco: Geography and Processes" by Raymond D. Watts, U.S. Geological Survey, Denver, Colorado; Richard Pelltier, U.S. Geological Survey, Denver, Colorado; and Peter Molnar, Colorado State University, Ft. Collins, Colorado
- "The Arroyo Problem in the Southwestern United States" Brandon J. Vogt, U.S. Geological Survey
- Rio Puerco project