Barbara Lawlor, Cardinal. Boulder County Open Space employee Holly O’Brien hefted the heavy metal post hole digger and punched into the rock-laden soil next to a collapsed shed. The hole was about three feet deep and every time she slammed the digger into the dirt, the hole grew deeper.

It was hard work and hot in the middle of a clear, sunny, late July day. O’Brien was digging a hole for an 8” by 8” beam that would support the new adit entrance shed for the Boulder County Mine.

Because the structure was part of an historic landmark, O’Brien, Wilson Burnham, and Alex Turner were preserving most of the lumber, numbering it to put back in its original place, except for the wood that had rotted. The original doors will be put back in place.

The Boulder County Mine was opened in 1870 and at the time it was the largest producing gold mine in Boulder County. It operated until 1942, when it was shut down during WWII.

“Rebuilding the adit has been in the plans for several years,” said Wilson, whose father-in-law was one of the miners.

Turner said the old mine entrance went back 24 feet, but one couldn’t go beyond 12 feet now. “When the miners went into the mine they had to pick up a number tag to take with them and return when they came back out. We are trying to restore the place where it hung.”

The entrance was the beginning of a mile-long tunnel that ended at old Cardinal and which had been blocked by a cave-in. The opening at the other end is covered by a grate. The last person working in the mine was Mike Smith of Nederland in 1974. Allied Chemical had leased the mine to bring out the gold, but found that it was not an economically feasible project.

In 1870, Stephen Conger followed the profitable gold and silver vein from the Caribou Mine. He discovered an accessible lode, which he named the Boulder County Mine.    Known as a rowdy town filled with brothels, saloons, and gamblers, Cardinal City was a booming metropolis with 1,500 residents.

A new town, New Cardinal, grew up around the mine.

In 1903, the Cardinal Mill was built at the mouth of the BCM tunnel.

By 1905, the mill operators looked to tungsten, and by 1910 was one of the only five full-time tungsten mills in the area. It eventually went back to gold processing in 1914.

In 2003, Boulder County purchased the Cardinal Mill from local Realtor Lexie Armitage, planning to preserve the building for the education and appreciation of future generations.

The mill’s restoration is one of largest projects of its kind in Boulder County. The restoration project was funded by a State Historical Fund grant, Boulder County and Historic Boulder.

The first phase was drainage improvements and the reconstruction of the west retaining wall, funded by the State of Colorado Division of Water Resources.

The second phase was the reconstruction of the mill itself, with repairs to the hopper roof, the north and east elevation, and the south elevation roof, columns, and beams. The roof, columns, beams, dormer, and windows were replaced.

Phase three rebuilt the east side retaining wall and made repairs to the eastern elevation wall and ore cart room.

Phase four included the repairs to the south and southwest elevation foundations and walls which had collapsed in the snow storm off 2003.

The renovation is paid for in part by a portion of the gambling tax generated by gaming in Central City, Cripple Creek, and Black Hawk. The State Historical Fund has awarded $254,155,509 in grants statewide since 1990.

The Cardinal Mill and the entrance to the Boulder County Mine are part of the BC Hard Rock Mining Tour, which includes the Argo Mine, the Assay Office in Wall Street, Caribou, the Blue Bird Mine, the Blue Jay Mine, Mammoth Mine, Horseshoe and Willie W Lodes.

The next BPOS event will be the “All That Glistens is not Gold” in Nederland on Saturday, August 22, from 11 a.m. to 1 p.m. The next Hard Rock Mining Tour is on Saturday, September 5, 10:30 a.m. to 1:30 p.m.

Every year another piece of our history is repaired and preserved so people can see what the buildings actually looked like, and they can hear the stories about the miners and their families who founded Boulder County mines back in the 1800s.

To sign up for these events, register with Boulder County Parks and Open Space: BoulderCountyOpenSpace.org