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U.S. DEPARTMENT OF THE INTERIOR
BUREAU OF LAND MANAGEMENT NEWS RELEASE
Safford Field Office
 
Release Date: 10/25/12
Contacts: Diane Drobka, 928-348-4403 ddrobka@blm.gov    

November BLM Brown Bag Talk
"Prehistoric Hanging Canals of the Safford Basin"


Safford, Ariz.  As part of Bureau of Land Management (BLM) Safford Field Office’s ongoing Brown Bag lecture series, Thatcher author and researcher Don Lancaster returns on Thursday, November 1, at noon.  His presentation will report on the latest updates and rediscoveries of a stunning world-class series of Safford-area mountain stream-fed prehistoric canals that are literally “hung” high on the edges of steep sided mesas.

There is no charge and families are welcome so bring your own “Brown Bag” and spend your lunch hour learning about these unique local features.  The BLM is located at the corner of 14th Avenue and 8th Street in Safford.

Over 21 hanging canals remain virtually unknown with a total distance of at least 40 miles.  The canals are believed to date from the 1350s.  Some have also seen historic adaptation and a few still remain in active use.

The construction of a hanging canal can be exceptionally energy efficient in that its slope can be made largely independent of terrain.  The high side of the canal is often “free” and construction can largely take place across rather than along the canal.

“In many places, the canals provide a strong illusion of “water flowing uphill,” said Lancaster.   “In reality, most of their slopes are at a nearly optimum downhill grade.”

The evidence suggests that virtually every drop of northeastern Mount Graham stream water was put to use.  While no survey tools are known to survive, “pilot extensions” of the canals themselves were thought to serve as water levels to establish the needed grades.

Many independent arguments verify the prehistoric origins of these canals.  These include roads, tanks, fences, dams, and even cemeteries that run roughshod over the canals without access or accommodation; large mesquite trees and barrel cacti mid-channel; uniform desert varnish, caliche, and lichens; absence of any apparent modern tool use; and, above all, a purposefulness that clearly and uniquely meets prehistoric needs.



The BLM manages more than 245 million acres of public land, the most of any Federal agency. This land, known as the National System of Public Lands, is primarily located in 12 Western states, including Alaska. The BLM also administers 700 million acres of sub-surface mineral estate throughout the nation. The BLM's mission is to manage and conserve the public lands for the use and enjoyment of present and future generations under our mandate of multiple-use and sustained yield. In Fiscal Year 2013, the BLM generated $4.7 billion in receipts from public lands.
--BLM--

Last updated: 11-05-2012