I don't believe anyone has mentioned the use of metal detectors at the Little
Bighorn Battlefield site, where 62 volunteers were used.  See Douglas D. Scott
and Ricahrd A. Fox, Jr., 1987, <Archaeological Insights into the Custer
Battle>, University of Oklahoma Press.  No indication as to whether any of
these were "amateur collectors" or not, though some were students at Sheridan
Girls School so presumably were not.
 
Jim Murphy
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