RESPEC Project

Historic mining of the alluvial gold deposit in the Yuba Goldfields had left a series of ridges and valleys of segregated sand and coarse aggregate. RESPEC reviewed historic gold-dredging records to determine the digging depths throughout the mining district based on the dredge used and the dredge track. Based on the digging depth, the various distribution of coarse-to-fine aggregate was determined based on the dredge conveyor discharge elevation and the location of the dredge flume. This distribution analysis defined the reserves that could be obtained from surface mining and the projected coarse-to-fine aggregate blend.

Additionally, RESPEC reviewed historic property mapping to develop an overall base map of the goldfields that were used to reference all data. The evaluation focused on the varying value of the property based on the historic mining depth, depth to groundwater, and the blends of coarse-to-fine aggregate. The evaluation indicated the variation in value depending on which portions of the property could be mined because of the varying value of coarse and fine aggregate.