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Overholser Mansion
Haunt Investigation
August 7th, 2004

Printable Version

Background & Site History

    This historic Victorian style home was completed in 1903 for Henry Overholser (1846-1915), a famous historical figure, sometimes called the "Father of Oklahoma City". This entrepreneur married Anna Ione Murphy (1872-1940), and was a key figure in erecting numerous businesses in what has become downtown Oklahoma City, including the Overholser Opera House, and Overholser Theatre. The mansion was a big part of the social scene in the early 1900's, until Mr. Overholser's death in 1915. Currently, the mansion is owned by the Oklahoma Historical Society, and preserved/managed by Preservation Oklahoma. Tours are available Tuesday through Saturday, 10:00am - 3:00pm, so be sure and stop by to help preserve this beautiful historic mansion's history. The mansion is located on the corner of 15th and Hudson, in Heritage Hills, near downtown Oklahoma City; please visit here for tour details and support this beautiful piece of Oklahoma's history.
   - Sources:  HENRY OVERHOLSER, Overholser, Henry (Mansion)

Reported Activity

    Reports of activity mainly occur in specific areas, and are typically described as subjective feelings of queasiness, anticipation, or fear, including psychic "impressions". Interviews with one of the Docents (herin denoted as "Docent A") showed several areas of interest, including the Nursery (2nd floor), Monroney Bedroom (2nd floor, NW bedroom), "Collections Area" (3rd floor, room adjacent to ballroom, currently used as storage), and the North "Carriage" stairway. Most reports are simply that of feelings of uneasiness, as described above, while in one case possible RSPK type activity was reported. As described by Docent A: "The miniature bathtub in the Nursery seems to move forward, a little bit at a time. I have never physically witnessed the movement, but it appears to be in a slightly different place each time I enter the room". This could not be verified as physical activity, so I suggested to place some sort of marker on the floor where the legs stand, so any possible movement could be monitored and recorded by the Docents in the future. On one occasion, Docent A reported visually seeing a light at the intersection of the North "Carriage" stairs, as well as uneasy feelings in one particular spot in this area.

    Some of the original residents reported a few odd experiences and feelings in the building as well. Mary Ellen Monroney, a previous resident, reported a feeling of uneasiness on the third floor, and described it as "spooky". Later on, a self proclaimed "spiritualist" was brought into the house, who also reported an uncomfortable feeling on the third floor. Several reports of witnessing the apparition of a young woman in white moving from the music room to across the hall on the first floor have been reported by different people.

Preliminary Findings & Hypothesis

    Three investigations of the Overholser Mansion had been held preciously by OPRA (Oklahoma Paranormal Research Alliance), which I attended two of, both with the Arcadia computer monitoring system. The first investigation (April, 2003) yielded mixed data, and little environmental correlation on Arcadia, but the second investigation (August, 2003) yielded some very interesting data. Variances seemed to be high in the static magnetic fields (1st floor), and a TriField Natural meter (on magnetic), set up in the Library, showed a large (10.5 mT) temporal field change. Reports of being touched were also noted by several team members, as well as a door on the 3rd floor opening by itself. I suspect to possibly find heavy local EM variances in the areas of interest (where uneasiness, anticipation, fear, and possibly RSPK activity has been reported), as well as possible infrasonic sound resonant frequencies, which can cause feelings of uneasiness and possibly fear. EM data (AC and static magnetic) will be logged continuously in several areas of interest, while electric fields and sound resonance data is being calculated for other areas in the mansion.

Investigation Held:    Measuring Equipment Used:
Solar X-Rays:
Geomagnetic Field:
AC EMF Fields (13 Hz -75 kHz):  3-Axis UHS AC EMF meter (AlphaLabs)
Electric Fields:  Multidetector II Profi (
Static Magnetic Fields:  Arcadia's Two-Axis Static Magnetic Field Meter
Computer Logging Interface:  Arcadia's A/D Converter

Library (1st Floor)

 Click to view graphs from this area:
   - AC Magnetic Fields Graph
   - Static Magnetic Fields Graph
    This was a follow up log for the large (10.5 mT) spike recorded on a TriField Natural meter during the second investigation, and also a control log for comparison to previous control runs in other areas (since little anomalous activity has been reported from this area). Measuring equipment was set up on the same table as the previous recorded fluctuation. Static magnetic fields showed minor fluctuations, mainly in the N-S axis, while AC magnetic fields show two large, nearly instantaneous spikes in field strength. The first spike, around the 1,835 second mark, jumps from .5 to .9 mG, and back down to about .6 mG. The second spike (3,595 second mark) was very similar to the first, peaking at 1 mG, both occurring within a 3 second time period. This could be due to nearby unseen electric appliances, such as an air conditioner, or other appliances that switch on and off sporadically. The spike field strength is very small (1 mG), but the quickness of the field change could trigger odd experiences. All EM fields showed less/equal variance (SD) when compared to previous typical control runs.

Field Means, Standard Deviations (SD) & Control Log SD for Comparison
Field Mean Strength SD Typical Control SD
Static Magnetic Fields: N-S: -170.303 mG 0.489 mG < 0.5 mG
Static Magnetic Fields: E-W: -208.163 mG 0.390 mG < 0.5 mG
AC Magnetic Fields: 0.523 mG 0.047 mG < 0.09 mG
Electric Fields: < 10 V/m in most areas, 80 V/m under chandelier

Collections Area (3rd Floor)

 Click to view graphs from this area:
   - AC Magnetic Fields Graph
   - Static Magnetic Fields Graph
    Docent A reports feelings of uneasiness in this room, adjacent to the ballroom, currently being used as storage. Measuring equipment was set up in the center of the room, approximately 5 feet off the ground. Static magnetic fields show instability on both axis, along with small, smooth variances. Frequencies between .01 and .02 hertz are apparent, but these oscillations are short lived, not seeming to last more than a few minutes for each. AC magnetic fields show similar spikes as the Library area had, suggesting that the house may have poor shielding and grounding. These spikes were much larger, the first occurring at 80 second mark, up to 1.45 mG, which then drops back down to about .79 mG. This new baseline holds for about 10 minutes, when the field strength then drops to about .6 mG. Another large spike up to 1.45 mG at the 1,460 second mark starts a baseline of .76 mG. After another 10 minutes, the field strength drops again to .6 mG, which holds until a spike of 1.6 mG occurs (2,840 second mark), and a .8 mG baseline is established. Just before the graph ended, the baseline dropped to just above .7 mG. The process seemed to follow a pattern, each spike occurring exactly 23 minutes apart, the cause of which is unknown (as mentioned above, possibly an air conditioner or other appliance). Electric fields were much higher than normal in this area, in some places over 200 V/m, which can cause odd feelings such as tingling, goosebumps, etc.. EM variance in this area showed to be a little higher than typical control runs.

Field Means, Standard Deviations (SD) & Control Log SD for Comparison
Field Mean Strength SD Typical Control SD
Static Magnetic Fields: N-S: -146.459 mG 0.566 mG < 0.5 mG
Static Magnetic Fields: E-W: -212.009 mG 0.665 mG < 0.5 mG
AC Magnetic Fields: 0.706 mG 0.109 mG < 0.09 mG
Electric Fields: < 30 V/m typically, in some places over 200 V/m

Nursery Room

 Click to view graphs from this area:
   - AC Magnetic Fields Graph
   - Static Magnetic Fields Graph
    Reports from Docent A point to possible RSPK type movement of the miniature tub shown in the photo. To get an idea of the EM fields in the area of the bathtub, measuring equipment was set up on the ground adjacent to it. Very strong (9.6 mG) AC baseline magnetic fields were found, most likely due to 60 hz mains wiring under the floor in this area. These fields fluctuated between 9.2 and 9.8 mG at various frequencies, from .017 to .05 hertz. Static magnetic fields in the N-S axis showed a similar oscillation (.017 to .026 hertz), but each frequency is short lived, not lasting more than a few minutes. The odd frequency oscillation and high peak-to-peak strength (~5 mG) in the N-S axis is something that I've never seen before, and could possibly be due to aliasing, caused by the large field strength of 60 hertz magnetic fields (10 mG). Static magnetic fields in the E-W axis show a similar oscillation, but not as high peak-to-peak strength (< 3 mG). The very strong AC magnetic field (9.6 mG) is much higher than the recommended exposure level for most countries, which is typically 2-3 mG at 60 hertz. EM variance in this area showed to be a MUCH higher than typical control runs, particularly in N-S static magnetic fields.

Field Means, Standard Deviations (SD) & Control Log SD for Comparison
Field Mean Strength SD Typical Control SD
Static Magnetic Fields: N-S: -228.729 mG 1.435 mG < 0.5 mG
Static Magnetic Fields: E-W: -185.557 mG 0.671 mG < 0.5 mG
AC Magnetic Fields: 9.548 mG 0.152 mG < 0.09 mG
Electric Fields: < 30 V/m, strongest in center of room

Monroney Bedroom

 Click to view graphs from this area:
   - AC Magnetic Fields Graph
   - Static Magnetic Fields Graph
    Docent A reported feelings of uneasiness in this room, particularly in one spot, near the bathroom. To get an idea of what kind of fields would effect the brain in this area, measuring equipment was setup 5 feet off the ground (this was the highest pedestal we could rig on-site without planning) at the same location where uneasy feelings were experienced. Immediately upon entering the area, I noted the smell of natural gas, which was then confirmed by Docent A, who said that the smell has been there for quite some time. It is unknown whether there could possibly be an old gas furnace in the area, but currently the mansion uses all electric appliances. This gas presence could be causing the feelings of uneasiness, as reported by Utilities Kingston gas/electric company, carbon monoxide in natural gas can "cause flu-like symptoms without a fever, including: headaches, nausea, dizziness, drowsiness or fatigue, burning eyes, confusion and loss of coordination". AC magnetic fields in this area shown minor fluctuations in the baseline, and just a few notable spike of about .15 mG above the baseline. Static magnetic fields showed some minor temporal changes of about 3 mG, with little oscillation compared to the graphs of other areas. At the beginning of the log, the N-S static magnetic field baseline shifted down about 2 mG, which could be due to the storm geomagnetic activity at the time. EM variance in static magnetic fields showed to be a higher than typical control runs, particularly in the E-W axis.

Field Means, Standard Deviations (SD) & Control Log SD for Comparison
Field Mean Strength SD Typical Control SD
Static Magnetic Fields: N-S: -117.0579 mG 0.571 mG < 0.5 mG
Static Magnetic Fields: E-W: -160.124 mG 0.918 mG < 0.5 mG
AC Magnetic Fields: 0.484 mG 0.043 mG < 0.09 mG
Electric Fields: 40-60 V/m

   Notes: AC magnetic fields in the isolated VLF region (1-75 khz) were measured for all rooms, but was found to be a constant 0 mG. Because of this, all AC magnetic field measurements can be assumed to be between 13 hz and 1 kHz, most likely 60 hertz (from power mains) for most areas. Electric fields for all rooms were measured at a height of 6' off the ground, and were typically < 10 V/m, except under lights/chandeliers, where 70-90 V/m would be found. During the logging sessions, the room being logged was left empty, and for most of the logs, the entire building was empty.

Resonant Frequency Analysis

    As described in the Handbook for Acoustic Ecology, "Infrasonic frequencies are felt as vibrations which, if intense enough, may result in feelings of nausea, vertigo and eventual black-out or internal hemorrhaging". These sound waves are under 20 hertz and can be produced by normal sounds if the resonant frequency of sound (how many times per second sound travels between a cavity and returns to its starting point). Resonant frequencies for some areas were calculated at room temperature (72 F) with the following formula: (1131.743 f/s) / (2 * Cavity Width (in feet)). Note that the 1131.743 feet/second figure is the speed sound travels at in room temperature, and frequencies below Alpha brain wave (< 13 hz) frequencies were flagged in red, as there is a possibility that these effect the body more than higher infrasonic frequencies. Notice the "Piano Room to Library" measurements, correlating with the reports of an apparition seen moving between the two rooms, and the 3rd floor ballroom measurements, where feelings of uneasiness have been reported by many.

Room resonant frequencies at 72 F Room resonant frequencies at 72 F
Area Measurement Resonant Frequency Area Measurement Resonant Frequency
Monroney to Master Bedroom (wall to wall) 51' 11.10 hz 3rd Flr, Ballroom to Exhibit Cases room (wall to wall) 57' 9.23 hz
Nursery 12' x 20' 47.16 x 28.29 hz 1st Flr, East Entryway, E-W (wall to wall) 40' 14.15 hz
1st Flr, Piano Room to Library, N-S (wall to wall) 52' 10.88 hz 2nd Flr, Guest Bedroom to Stairway wall, E-W 45' 12.57 hz


    As expected, noticeable environmental correlation was found between the various phenomena experienced in certain areas, and natural variables in each area. The noticeable correlations included many different variables, including the presence of standing natural gas, standing infrasonic waves, high magnitude of AC magnetic fields, high variance in static magnetic fields, and high electric fields. The fact that so many different environmental correlations were found makes it desirable to focus more research on each individual variable or room one at a time. For some areas, it may be possible to actually isolate the source of, for example, the standing natural gas, in which case the phenomena in that area could be minimized, if not stopped all together. This is an on-going investigation, so be sure to check back regularly for more updates, and be sure to visit by the beautiful Overholser Mansion and support the preservation of history! Special thanks to the Oklahoma Historical Society, Preservation Oklahoma, and all the docents/caretakers at the Overholser Mansion!

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