BLACK HAWK HISTORY – GREGORY DIGGINS
John H. Gregory first discovered gold in Colorado in 1859. The narrow ravine in which he panned the free or surface gold, was hailed as “the richest square mile on earth.” Within months, as the word GOLD! spread, Gregory Gulch filled with thousands of miners.
Placer mining was slow, hard work, Miners dug the gulch with picks and shovels, deposited the gravel in tin pans, then washed the sand, dirt and gravel from the gold. Miners quickly innovated the sluice box creating a more efficient and larger-scale washing technique. Gravel was shoveled into a continuous wash of water. The heavy gold sank to the bottom of the sluice and was captured by cleats or riffles. Mercury placed between the riffles bonded with the gold and kept finer gold from washing away.
“…before the first of July  there were not less than one hundred sluices running in Gregory gulch
and below…the production was from $20 to $30 per day to the hand.”
The Gold Mines of Gilpin County, Colorado, 1876
As placer mining and sluicing exhausted the free gold, miners began digging into the ravine’s rock sides searching for buried veins or pockets of gold. Hard rock mining required more money, men, machinery and buildings.
“Turning into Gregory Gulch, we slowly mounted through Black Hawk and Mountain City to this place; but all three places form in reality one continuous town, more than two miles long, and with over six thousand inhabitants. The houses are jammed into the narrow bed of the canyon, employing all sorts of fantastic expedients to find room and support themselves. Under them a filthy stream falls down the defile over a succession of dams. It is a wonderfully curious and original place…”
World traveler, Bayard Taylor, Colorado: A Summer Trip, 1867
“The discovery of the lode called after himself, by John H. Gregory would seem to rank among those events whereby the race at large has profited.”
Ovando Holister, 1867