Documents from the G. M. Colvocoresses mining collection. Description: Map of claims 1':300, Map showing workings and samples of mine 1':30, Report of assay by DeCamp, Letter from Wester Precipitation Company, Letter from Madonna Corporation, Correspondence between Colvocoresses and Giroux, Log of samples taken, Reports on mining claims by Giroux and McConnell, Letter from O'Brien regarding development, Report by Tovote, Report by Trischka. Property Name: Black Rock. Property AKA: Pacific Mines
