Santiago Mill

The historic mill is located on National Forest System land

Santiago Mill History

Santiago Mill is an increasingly rare example of an early- to mid-20th century American floatation mill located on National Forest System lands. Built in 1935, the mill was used for concentrating locally mined gold, silver and lead ore, utilizing the floatation process. It is one of the last complete depression-era mills standing.  The Santiago Mill is listed on the Colorado State Register of Historic Properties.

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.


Santiago Mill safety

The U.S. Forest Service recently completed soil remediation work at the historic Santiago Mill site to remove harmful toxins including arsenic, lead and mercury. Most of the area around this mill has reopened, however thesteep hillsides around the mill and th mill itself remains closed due to unsafe conditons -- click to see a map. The open mine shafts and the mill are unstable and unsafe. Do not go near the opening of the mine. The shaft could collapse and the unventilated air inside could expose you to undetectable fatal gases.

Historic Georgetown Inc. is sponsoring the Santiago Mill Stewards, a group of volunteers working to provide information to the public at the Santiago Mill site and helping the
U.S. Forest Service plan for future interpretive and educational opportunities once the area reopens. To get involved, contact 303-569-2840.


Georgetown Historic Trust

Georgetown Visitors Center

History Colorado