• Catspaw Minerals.

Here is a link to an article about how to install MRDS overlays into Google Earth, which sounds like something with a lot of potential.

I have not been able to track down the now historic original MASMILS data (which Catspaw says is 7000 files describing 210,000 mines). This is of no real concern, given that MASMILS was assimilated into the larger MRDS (Mineral Resource Data System) project.
Incidently, in case you were wondering, MAS/MILS stood for Mineral Availability System/Mineral Industry Locator System.

The MRDS web site is:

• MRDS main website

A tool is available that makes this easy to handle this on my linux system:

• DBF
• DBF downloads

dbf --csv mrds.csv mrds.dbf

"DEP_ID,C,12","MRDS_ID,C,7","MAS_ID,C,10","SITE_NAME,C,70","LATITUDE,N,8,5","LONGITUDE,N,9,5","REGION,C,2","COUNTRY,C,32","STATE,C,53","COUNTY,C,40","COM_TYPE,C,1","COM_MAJOR,C,125","COM_MINOR,C,129","COM_TRACE,C,161","OPER_TYPE,C,19","DEP_TYPE,C,40","PROD_SIZE,C,12","DEV_STAT,C,13","ORE,C,128","GANGUE,C,128","OTHER_MATL,C,210","OREBODY_FM,C,60","WORK_TYPE,C,27","MODEL,C,75","ALTERATION,C,200","CONC_PROC,C,255","PREV_NAME,C,255","ORE_CTRL,C,200","REPORTER,C,128","HROCK_UNIT,C,128","HROCK_CODE,C,37","AROCK_UNIT,C,128","AROCK_CODE,C,38","STRUCTURE,C,255","TECTONIC,C,96","REF,C,255","YFP_BA,C,1","YR_FST_PRD,N,4,0","YLP_BA,C,1","YR_LST_PRD,N,4,0","DY_BA,C,1","DISC_YR,N,4,0","PROD_YRS,C,64","DISCR,C,64"

"10000001","A010000","","Lookout Prospect",55.05639,-132.1416,"NA","United States","Alaska","Craig","M","Copper","Silver, Gold","","Unknown","","No","Occurrence","Chalcopyrite, Covellite, Pyrite","Quartz, Sericite","","","Surface/Unde","","","","{Wakefield Minerals Co.}{Mammoth}{Conundrum}","","Hirschmann, M. M. (Elliott, R. L.)","","150","","","Schist Strikes N65w, Dips 70sw","","{Deposit:: USGS PROFESSIONAL PAPER 1, P. 75-77.}{Deposit:: USGS BULL 347, P. 131.}{Deposit:: USGS BULL 1246, P. 174}{Deposit:: USGS MF 433}{Deposit:: USGS OF 78-869, P. 117}","",,"",,"",,"",""

"10000002","A010001","","Lucky Find Prospect",55.52778,-132.6833,"NA","United States","Alaska","Craig","M","Copper","Gold","","Unknown","","No","Occurrence","Chalcopyrite, Pyrite","Calcite, Quartz, Siderite","","","Underground","","","","","Vein Follows Contact","""Hirschmann, M. M. (Elliott, R. L.)"", ""Mosier, Dan""","","115","","","","","{Deposit:: USGS BULL 347, P. 165.}{Deposit:: USGS MF 433}{Deposit:: USGS OF 78-869, P. 120.}","",,"",,"",,"",""

"10000274","M002610","","La Colorado Mine",33.00444,-114.1686,"NA","United States","Arizona","Yuma","B","Lead","Silver, Fluorine-Fluorite","Copper, Barium-Barite, Molybdenum","Unknown","Vein","Small","Past Producer","","Barite, Calcite","Fluorite","LENSES, SPOTTY BUNCHES & POCKETS","","","Silicification, Sericitization","","{Castle Dome Mine Group}{Lincoln Mine}","Along Fissures At Shale And Limestone Contacts With Diorite Porphyry Dikes","""Gere, W."", ""Hall, R. K. (Creasey, S. C.)"", ""Orris, Greta J.""","","24,40","Kofa Volcanics","114","","Block Faulting","{Deposit:: U.S.B.M. CARD FILE.}{Deposit:: WILSON, E.D., 1951, ARIZONA ZINC AND LEAD DEPOSITS:  ARIZ. BUR. MINES BULLETIN 134, P. 114.}{Deposit:: WILSON, E.D., 1933, GEOLOGY AND MINERAL DEPOSITS OF SOUTHERN YUMA COUNTY, ARIZONA:  ARIZ. BUR. MINES BULLETIN","",1901,"",1949,"",,"",""

"10008137","D000070","","Bridal Veil Claim",36.23333,-112.7,"NA","United States","Arizona","Coconino","M","","","Vanadium, Copper, Zinc, Lead","Unknown","","No","Occurrence","","","","","","","","","","","Fischer, Richard P.","","","","","","","ALLEN, M. A. AND BUTLER, G. M. 1921, UNIV. OF ARIZ. BULL. 115, P. 1","",,"",,"",,"",""

"10008138","D000074","","Aurora Mine",35.40944,-114.1805,"NA","United States","Arizona","Mohave","M","Vanadium, Lead","Silver","","Unknown","Vein","Small","Past Producer","Vanadinite","","","","Surface/Unde","","Oxidation Zone Contains Pb + Ag","","","","Johnson, Kris H. (Creasey, S.C.)","","94","","94","Prec Schistosity N30e, Lcret Veins, Fissures, Dikes Nw To Nnw Regionally","","DINGS, M.G., 1951 , THE WALLAPAI MINING DISTRICT, CERBAT MOUNTAINS, MOHAVE COUNTY, ARIZONA, U.S.G.S. BULL. 978-E, PP 148-149","",,"",,"",,"",""

"10008139","D000075","","Lincoln Claim",34.5,-112.2666,"NA","United States","Arizona","Yavapai","M","","","Vanadium, Copper, Zinc, Lead","Unknown","","No","Occurrence","","","","","","","","","","","Fischer, Richard P.","","","","","","","WALDEMA","",,"",,"",,"",""