Santiago Mill added to Colorado’s State Register of Historic Places

Contact(s): Elsha Kirby

IDAHO SPRINGS, Colo. –In partnership with Colorado State Abandon Mines, Georgetown Trust for Conservation and Preservation, Historic Georgetown Trust, and Friends of Santiago the U.S. Forest Service was able to add the Santiago Mill, near the city of Waldorf in Clear Creek County, to Colorado’s State Register of Historic Places.

The U.S. Forest Service, Colorado State Abandon Mines Program, and the Georgetown Trust for Conservation and Preservation started work under a Challenge Cost Share partnership in November 2012 to reconstruct the mill’s gable roof to original dimensions and stabilize the crusher tower, deterring destruction of the mill.

The Santiago Mill is an increasingly rare example of early to mid-20th century American floatation mills located on National Forest System lands. It is one of the last complete depression-era mills standing.

Built in 1935, the mill was used for concentrating locally mined gold, silver, and lead ore utilizing the floatation process. Designed to save on power costs, the mill utilized gravity to process ore extracted from the Santiago Mine and surrounding dumps. Floatation was a cost effective way to process heavy mineral particles out from lighter waste particles by “floating” the waste from the mineral using water.

Prominent features of the mill site include the 1935 mill and sampling shed, 1948 water tank, and 1911 ore bin. The mill is a shed-roofed, wood-framed building with four steeped bays. On the northeast side of the mill is a single story gable-roofed with a shed-roofed addition called the sampling shed.

The mill itself contains remnants of milling equipment from the 1930s through the 1950s. The 3,700 gallon water tower, critical to the floatation process is found northeast from the mill. This tower was filled by a piping system from snowmelt collection higher up the slope and another welded pipe, a half-mile long that pumped water from the town of Waldorf below.

Through a partnership with Historic Georgetown Trust approximately 30 volunteers educate the public of the rich history of Santiago Mill.