Satanic Bluebird Drilling Investigation Project
The Satanic Bluebird Drilling Investigation will be taking place during late 2023 near W. Alameda Parkway and S.
McIntyre Street in Lakewood, CO. The purpose of the investigation is to explore the main hoist shaft and the air
shaft of the old Satanic/Bluebird coal mine to determine the subsurface conditions that may cause unsafe
conditions of the surface lands.
History
Otis Rooney (eldest son of Alexander) started the Satanic Mine around 1872, which included a number of
outbuildings and 4-story hotel that housed 77 men. The hoist foundation and foundations for the mule shed and
machine building remain.
Mine maps indicate the mine was in nearly vertical beds (dipping east at 85 degrees) 8-10 feet thick to a depth
of 680 feet below ground surface. The mine contains at least 17 recorded levels of coal extraction with a triple-
chambered hoist shaft descended into the mine to allow coal removal and men to enter and exit the subsurface
workings.
On December 3rd , 1921, 6 miners were killed by a coal dust explosion while trying to stop a mine fire. After an
investigation, the air shaft to the north was advanced to help with ventilation and the mine was renamed the
Bluebird Mine. The mine shut down in the mid-1930s during the Great Depression.
There have been a number of documented subsidence occurrences relating to the mine workings in the late half
of the 1900s. Currently the site is owned by the City of Lakewood and is zoned as Open Space.
Problem
No documentation of closure of the mine shafts exists. We do not know if or how the shafts were closed
properly or just filled with debris (as was common practice in the early mining days). If substantial voids still
remain in the shafts, they could open up over time, creating a significant safety hazard to people and animals in
the area. Steeply dipping mines easily propagate voids to the surface and have caused damage to property along
the Denver Basin boundary where they exist.
This area of Jefferson County is under increasingly high development pressure with new high-density residential
development occurring or being proposed on the surrounding lands, and open space to the north drawing
recreationalists from across the region to the area. The large depression with mature cottonwood trees over the
suspected hoist shaft is an attractive area for nearby public to want to explore, particularly children.
Widening of local roads and nearby development has increased water runoff into the area following rain events.
The main hoist shaft area has been observed holding water after heavy rains, increasing the potential for a soil
plug to fail.
The mine depth, geology, and multiple levels of mining poses a high hazard if collapse were to occur.
Investigation Activities
The Satanic Bluebird Drilling Investigation Project will consist of several tasks. Field work is expected to be
completed within 22 days, weather allowing.
- Build safe drilling platform in area of hoist shaft.
- Drill 3 preliminary “probe” angled borings to 20 ft to determine safest approach over hoist shaft. (Safety
of workers) - Drill up to 6 holes in hoist shaft to max depth of 220 ft to determine location and condition of each
chamber - Drill up to 7 holes along air shaft alignment to determine location and condition of the incline to point
where subsidence not likely to cause hazard at surface. - Cased downhole hammer for upper 30 feet, uncased downhole hammer below 30 ft. Vertical drilling will
include Standard Penetration tests at 5-ft intervals to 80 ft bgs, then at 10 ft intervals to total depth. Drill
cuttings will be evaluated for evidence of mine workings. - Up to 16 borings total, 1500 linear feel max.
- Borehole camera will allow observation of voids encountered during drilling.
- Geophysical survey will be used to measure borehole deviation at depth as needed.
Drilling Investigation Goals and Mitigation Strategy
The goals for the Satanic Bluebird Drilling Investigation Project are as follows:
- Determine the location and condition of the triple chambered main shaft.
- Determine the location and condition of the air shaft.
Depending on the Drilling Investigation results, followup work may also occur:
- If voids are present, subsequent pressure grouting would be done to stabilize the shaft(s) and minimize
surface expressions that could create a safety hazard. - Site reclamation to restore the site vegetation in work areas with native grass and forb species.
- DRMS will work with the City of Lakewood to understand potential risks to future development in the
area and provide information to the Colorado Geological Survey Land Use and Geologic Hazards
Program.
PROJECT UPDATE 11/16/2023
Equipment will be mobilized to the site the week of November 20. Construction on the drilling platform will
begin the week of November 27, weather permitting.
PROJECT UPDATE 12/18/2023
The drilling work at the Satanic Bluebird site is complete. The geotechnical report will be drafted in the upcoming months, and likely mitigation work will be done in the fall of 2024.
For additional Information, contact TC Wait at tc.wait@state.co.us