05/13/2026
This Saturday!
Public Talk: Beavers on the San Pedro River
Join the Friends of the San Pedro River and the Friends of the Huachuca Mountains at 1:30 pm on Saturday, May 16th at the large auditorium at the Sierra Vista Public Library for the talk "Beavers on the San Pedro River" by Dr. Steve Merkley and Mr. Frank Emanuele, biology instructors at Cochise College.
Once plentiful, beavers were gone from the river early by the early 1900s. The lower San Pedro River was called Beaver River by trappers in the early 1800s because it boasted a large population of beavers and beaver dams. Beavers disappeared because of several factors. To end malaria outbreaks in Army posts near the river, the Army dynamited beaver dams. A series of major floods in the 1890s and early 1900s washed away dams and downcut the river bed. Finally, trapping reduced the population.
The removal of the beavers was a major cause of the transformation of the river from a slow-moving, surface level stream notable for its cienegas and ponds into a downcut, faster, straighter channel that did not retain moisture.
North American beaver (Castor canandensis) were reintroduced into the Upper San Pedro River in 1999 by Arizona Game and Fish in cooperation with the Bureau of Land Management. This was done to restore a native species, with the hope that the beavers would help restore the river to its natural state. Beavers prospered for a decade, then began to decline. Today, numbers are reduced and there are only a few areas where beavers are living.
During this talk, the speakers will highlight beavers' impacts on the river and its native wildlife. They will also describe how DNA collection has been used as a tool to explore beaver population diversity.
For more information, call (520) 508-4445 or email [email protected].
