Linda,
 
You may want to look at: reports generated by William White in Nevada
regarding mining camps and ethnicity; Mitzi Rossillon in Butte, MT has done
extensive work on Montana  mines; Jim Calvi of Libby, MT has researched and
dug numerous mining sites and delved into the ethnic question; Julia
Costello in California has worked on Cali. mining sites for over 20 years;
Priscilla Wegars at U of Idaho has done much work on ethnics of eastern
Wash. and northern Idaho.  These are the more prolific ones that come to
mind instantly.  I just finished my thesis on ethnics working on the Great
Northern and Northern Pacific.  I'll send you that bibliography if you'd
like.
 
Best,
 
Stacy Culpepper