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July 14, 2020

Nomination Cites Ute-Ulay Complex as ‘Incredible Resource’


In his successful nomination seeking listing of the Ute-Ulay Mine to the National Register of Historic Places, Jon Horn of Alpine Archaeological Consultants states “mining and milling sites in Colorado with standing architecture and associated archaeological components in good condition are relatively rare.”
Continuing, he says “those that have surviving elements that date over such a long period of time — in this instance from the 1870s to the 1960s — that can be readily observed and interpreted are almost unheard of. The potential the Ute-Ulay Mine and Mill has for interpretation and understanding of the entire range of hardrock mining in the San Juan Mountains is unsurpassed.”
In his report, Horn states that in addition to numerous sites and features with notable historic context, the Ute-Ulay complex consists of a total of 35 structures apparently dating from as early as the 1880s and continuing up through the early 1960s.
While remnants of the mine’s earliest development in the 1870s and 80s remain — notably log and frame residences, the wood frame business and assay offices, boarding house and storage buildings — much of the cmplex dates to a later era approximately 1926 to 1930 when development was pushed by Michael Burke.
Burke’s best known additions to the existing mine complex are the trademark concrete dam which hovers over Henson Creek, and the mammoth, 37’-wide by 96’-long, seven-level concentrating mill building.
The mill remains almost entirely furnished with original equiment which was used to incrimentally reduce sizeable chunks of silver and lead ore to a refined powder concentrate suitable for shipping.
The c. 1928 mill starts at its upper levels with an ore bin and crushing shed near the mine portal which remains emblazoned with the date “1926” on its concrete surround. From the ore dump shed/tipple, the roughly crushed ore was dropped to a now-absent jaw crusher and then passed by conveyor belt to ore storage bin.
Subsequent stages of the ore refining process remarkably illustrated in the mill building consist of a metal ball mill to further crush the ore, after which the pulverized ore was fed into a screw lift preceding a series of floatation tanks at mid-level in which the ore was agitated and swept about with paddle-like “plows”.
The end result, seen at lower levels of the mill was a frothy “ore pulp” which overflowed from 12 floatation tanks into troughs into a filtration tank. Wet concentrates, now reduced to a sandy configuration, passed from filter tank via chute to the rotary drier which consists of a metal pipe heated with a propane heater.
The very lowest portion of the mill expelled a powdery concentrate which could be loaded into drums for transport. Effluent in the process was handily ejected from the mill at various locations and routed to nearby settling ponds. The heavily contaminated settling ponds were intensely mitigated through work by Colorado Dept. Public Health & Environment and the EPA in 2009 and 2013.
The Ute-Ulay Complex is particularly important, according to Horn, as an illustration of incrimental advancements in mining technology. Early power to the complex was furnished by water power diverted from Henson Creek for use in an impresesive array of steam boilers. Water passed from dam via a 160’-long flume, remnants of which still exist, then to a lofty water tank which directed the water to three Leffel turbine water wheels by way of three existant 2-1/2’ vertical water pipes.
Water power was used in the steam boilers which in turn powered mining machinery including rock drills and 24-hour pumps to dewater mine tunnels which were located beneath Henson Creek.
Water from the creek was later utilized to generate electricity to power the mill and various
other mine workings up until about 1951. Thereafter electric power for the plant was furnished by the extant World War II-vintage marine Buckeye Diesel engine.
In addition to the 1928 concentrating mill, Horn also carefully documented other existing buildings in the complex, including the 28’ x 48’, 1-1/2 story frame boarding house which he attributes to the 1880s with subsequent additions, including a large shed dormer, as it was successively reconfigured as residence and bunkhouse.
He considers the mill building in “excellent condition” with some slight deterioration, other buildings in the complex ranging from “fair to good,” some noted as deteriorated condition, while others, Horn concludes “are remarkably good.”
He picked up and analyzed numerous glass and pottery chards throughout the site, attributing some to England-produced hotel ware and a range of glassware from liquor, food, and patent medicine bottles. Horn concludes that many areas within the county-owned mine complex have “excellent potential” for archaeological investigation which will further illustrate and expand the site’s recorded history.
Horn in his National Register nomination was intrigued by vestages of the original steam-powered mill, which survived until the early 1960s when it was emptied of equipment and demolished, and remnants of a rare surface tramway which conveyed ore from the Ute Mine higher up on the mountain slope down to the milling facilities just above Henson Creek.
In investigating the cable-based surface tramway, Horn documents the large cable roller which was used in lowering and raising the mine cars. The cable roller, according to Horn, “is the only one known to exist in the state.”

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