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Ajax Mine, Cripple Creek District, Teller Co., Colorado, USA

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Latitude & Longitude (WGS84): 38° 42' 56'' North , 105° 8' 32'' West
Latitude & Longitude (decimal): 38.71556,-105.14222

The Ajax mine was one of the more productive mines in the Cripple Creek – Victor District and one of the last significant underground operations. The headframe and other surface buildings stand on the lower slopes of Squaw Mountain just to the northwest of the center of Victor. In the mid 1970’s, after 15 years of dormancy and shortly after the price of gold was deregulated, an attempt was made to bring the Ajax Mine back into production. In the fall of 1977 this author had a chance to tour the mine, help measure some stopes and collect a few chips from a newly opened vein.

Activity at the time was focused on the 3100 foot level. On 3100 there were several old stopes that were being investigated as potential producers. In a short drift just off one of the main haulage ways a new vein had been exposed. I was impressed by how non-descript it looked, not really sheeted but more like jointing. However, on close inspection, the surfaces of some of the fractures were coated by thin layers of gray, almost flinty silica upon which were implanted small silvery crystals of calaverite. Other surfaces were coated with small crystals of calcite, a few tiny purple fluorite cubes and sparcely scattered calaverite. Since this area was just beyond the margin of the Cripple Creek volcanic basin the country rock was granitic. There didn’t seem to be any visible alteration of the country rock.

Very near the short drift on the new vein was the terminus of the Carlton drainage tunnel. This tunnel was driven just before WWII to enhance the drainage of the deeper workings in the Victor area. At the entrance to the tunnel were two simple, swinging metal doors with a gap of a few inches beneath their lower edges and a small amount of water running under them. Looking down the tunnel, it was so straight that it was possible to see the portal, a star-like pinpoint of light over 6 miles away.

Part of the normal equipment carried around in the Ajax Mine was a safety lamp of the type more common in the coal industry. In the Ajax Mine its purpose was not to detect methane but carbon dioxide. The day I worked underground was during a period of atmospheric high pressure which suppressed the release of CO2. One had to look closely into the stream of water running in the ditch at the edge of a haulage way to see the CO2 bubbles rising out of cracks in the rock. However, I was told that at times when an atmospheric low pressure system passed over the area the release of CO2 increased to the point where it could become a problem. In the old days if miners couldn't see the Sangre De Cristo Mountains because of storm clouds the chances were they wouldn't work that day.

In the 1970’s and 80’s underground mining proved to be to costly. A few years later open pit mining began just north of the Ajax mine. In the early 1990’s this effort became known as the “Cresson Project”. This has become a large open pit centered on the site of the Cresson Mine. The southern margin of the pit is now in the vicinity of the Ajax Mine.

Mineral List

17 valid minerals.

Regional Geology

This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.

Click on geological units on the map for more information. Click here to view full-screen map on

1600 - 2500 Ma
Granitic rocks of 1700-m.y. age group

Age: Proterozoic (1600 - 2500 Ma)

Stratigraphic Name: Boulder Creek Granite; Cross Creek Granite; Denny Creek Granodiorite; Kroenke Granodiorite; Browns Pass Quartz Monzonite; Powderhorn Granite; Pitts Meadow Granodiorite; Bakers Bridge Granite; Tenmile Granite

Description: Includes Boulder Creek -M.Y. AGE GROUP (AGE 1650-1730 M.Y.)--Includes Boulder Creek, Cross Creek, Denny Creek, Kroenke, Browns Pass, Powderhorn, Pitts Meadow, Bakers Bridge, and Tenmile Granites, Quartz Monzonites, or Granodiorites; also, unnamed granitic rocks

Lithology: Major:{granite}, Minor:{granodiorite,quartz monzonite}

Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. [133]

Data and map coding provided by, used under Creative Commons Attribution 4.0 License

This page contains all mineral locality references listed on This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.


Econ Geol (1985) 80:1669-1688

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