Estimates ranged between .03 and .05 of an oz. per cubic yard of alluvial gravels from what I recall. Conservatively .04 of an ounce was used to estimate production. There was a sticky that had it all broke down but that has been removed perhaps someone still has a cached copy of it they can share!! I really wish they would finish updating the website and take the mystery factor out of this...There was alot of good information there....I know new investors would like to see the website current to alleviate apprehension!!