The Hanging Flume was an open water chute (known as a

flume A flume is a human-made channel for water, in the form of an open declined gravity chute whose walls are raised above the surrounding terrain, in contrast to a trench or ditch. Flumes are not to be confused with aqueducts, which are built to tr ...

) built over the

Dolores River The Dolores River is a tributary of the Colorado River, approximately long, in the U.S. states of Colorado and Utah. The river drains a rugged and arid region of the Colorado Plateau west of the San Juan Mountains. Its name derives from the S ...

Canyon in

Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...

. The Montrose Placer Mining Company built the flume in the 1880s to facilitate gold mining. Some sections of the flume remain attached to the canyon wall, although much of the wood has vanished.

Background

The Montrose Placer Mining Company was formed to mine gold from

placer deposits In geology, a placer deposit or placer is an accumulation of valuable minerals formed by gravity separation from a specific source rock during sedimentary processes. The name is from the Spanish word ''placer'', meaning "alluvial sand". Placer min ...

along the Dolores River.

Hydraulic mining Hydraulic mining is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment.Paul W. Thrush, ''A Dictionary of Mining, Mineral, and Related Terms'', US Bureau of Mines, 1968, p.560. In the placer mining of ...

, a popular method of exploiting placer deposits, required water to be efficiently transported, often using wooden flumes to maintain the necessary volume and pressure. Cliffside flumes were developed in California, using trestles and brackets (called ''bents'') at regular intervals to support the flume box. The flume connected with a long ditch, both designed to provide water for miners in the

San Juan Mountains The San Juan Mountains is a high and rugged mountain range in the Rocky Mountains in southwestern Colorado and northwestern New Mexico. The area is highly mineralized (the Colorado Mineral Belt) and figured in the gold and silver mining industry ...

of Colorado.

Construction

Construction of the Hanging Flume took three years, beginning in 1887. Approximately 24 workers most being Asian immigrants, unwillingly participated in the build, suspended from ropes onto the cliff face. A

derrick A derrick is a lifting device composed at minimum of one guyed mast, as in a gin pole, which may be articulated over a load by adjusting its guys. Most derricks have at least two components, either a guyed mast or self-supporting tower, and a ...

may also have been used. The construction used 1.8 million board feet of lumber and ended up with a total cost over $100,000. The timber used was mostly

Ponderosa pine ''Pinus ponderosa'', commonly known as the ponderosa pine, bull pine, blackjack pine, western yellow-pine, or filipinus pine is a very large pine tree species of variable habitat native to mountainous regions of western North America. It is the ...

, a local tree, and it was supported using iron rods. The completed flume was approximately long and up to above the river. It began on a dam on the San Miguel River above

Uravan, Colorado Uravan (a contraction of uranium/vanadium) is a former uranium mining town in western Montrose County, Colorado, United States, which still appears on some maps. The town was a company town established by U. S. Vanadium Corporation in 1936 to e ...

. The flume's opening (the ''headgate'') no longer exists, and the connecting ditch has been filled. The actual wooden flume was 6 feet wide and 4 feet deep. When in use, it conveyed 80,000,000 gallons of water each day. The flume was only used for three years before being abandoned. The reason was that the mine itself was closed after the discovery that most of the gold was unrecoverable, and the investors in the project only made $80,000 after investing over $1,000,000 into the mine and associated engineering works. After the closure of the mine, local residents reused the timber.

Research and conservation

The Hanging Flume is in poor condition: it has been vandalized in places, some of its wood has been removed, and what remains has deteriorated, particularly where directly exposed to weather. The pine wood is vulnerable to decay and fungi. In April 2004, structural engineers rappelled down to the structure at seven locations to measure and evaluate it. They examined the design of the structure, particularly the bents, of which they identified five distinct types. This preliminary analysis is being used to consider a reconstruction of the flume incorporating the remaining structural elements.

Background

Construction

Research and conservation

References

Further reading