Historical Accounts of Arroyo Cutting in The Southwest: A Brief Outline and List of Accounts
— Scott B. Aby

This short paper presents a summary of historical information gathered on the timing and causes of arroyo cutting in New Mexico, Arizona, Colorado, and Utah, inspired by Kirk Bryan’s suggestion from almost a hundred years ago. The data discussed here, as well as the geologic and historical context of arroyo-cutting, are more fully treated by Aby (2017). Arroyo cutting has long been said to have happened mainly in the late 19th century. This compilation (Appendix 1; Figs. 1 and 2) of arroyo-cutting events largely confirms this, but also shows that significant numbers of events occurred in the early 20th century and some as early as the 1860s—possibly the 1760s. The history of the long-running debate about the causes of arroyo cutting in the American Southwest is beyond the scope of this
paper, but several summaries are available (e.g., Tuan, 1966; Graf, 1983; Betancourt, 1990). In short, climate change and overgrazing have often been suggested as causes of historical arroyo cutting, but climate changes are, in general, not in phase or synchronous across the study area, and the effect of grazing on incision, from a process standpoint, is not clear (Aby, 2017 and references therein).