Black Mesa Survey – New Oklahoma State Highpoint Location

Black Mesa, Oklahoma State Highpoint Survey

Oct 17, 2026

10 miles, 6am – 12pm

Eric Gilbertson

Results: New state highpoint location identified 440ft WNW of traditional summit marker, at 4976.3ft +/-0.2ft NAVD88, location (36.9320992, -102.9992865), 1.4ft taller than traditional summit location.

Introduction

I was visiting Colorado for some other objectives so decided to bring my surveying equipment and settle some uncertainty about the nearby Oklahoma state highpoint location. The uncertainty was identified by Ben Loftin after analyzing LiDAR data (elevation data taken by an airplane bouncing signals off the ground). The state highpoint of Oklahoma is the highest point on Black Mesa, a plateau near the CO-OK-NM tripoint.

History

Black Mesa was first surveyed in 1928 by Frank Hughes of USGS and J. Stone of the Oklahoma Geological survey. They performed standard leveling and measured the highpoint as 4,978ft. Later that year a stone monument was constructed at the location identified as the highpoint. It was constructed from blocks of black volcanic lava and malpais hauled up by horses and laid in cement mortar, with a 600lb 1.5ft x 1.5ft x 1.5ft granite cube placed on top, donated by the Pellow brothers of Kenton, OK. This monument was created in 1928, with a dedication ceremony on July 4 in Kenton. (Source: https://gateway.okhistory.org/ark:/67531/metadc2191689/m2/1/high_res_d/1929-v7-n1_a03.pdf )

On May 9, 1954 the summit was surveyed again, this time by C.A. Stoldt and G.H. Stout, at the direction of the governor of Oklahoma Johnston Murray. They found an elevation of 4,972.97ft. Members of the survey party included W.N McLaughlin Chief, C.D. Son, James Berry, E.M. Gladney, F.E Hill, H.C. Husted, H.C. Husted, A.R. Irwin. (Source: https://www.hmdb.org/m.asp?m=247159 )

In 1960 the original 1928 monument was torn down and replaced with an 8ft tall granite obelisk donated by Willis Granite Products of Granite, OK. The granite cube of the old monument was removed and the malpais boulders left on the ground near the new obelisk. A benchmark was set in the concrete at the base of the new obelisk reading 4,972.97ft.

 

2026 Measurements

I first climbed Black Mesa in 2009 with Matthew and we went to the traditional location. However, in 2019 LiDAR measurements were taken of the plateau and a point about 440ft to the west had the highest return, 1.0ft taller than the the highest ground returns at the traditional summit location. In general the entire ground 440ft to the west (hundreds of LiDAR returns) was taller than most returns around the traditional monument. This called into question whether the traditional summit location was correct. I’ve previously found through my research that LiDAR measurements for mountain summits elevations like this can have errors of +/-1.7ft (source: https://doi.org/10.1177/03091333251401361) so the LiDAR data was not definitive.

The LiDAR measurements were complicated by the fact that many boulders left over from the dismantled 1928 monument were laying on the ground nearby in the traditional summit area. These are not natural features of the mountain since they were hauled up by horses from other locations, so they do not count towards summit elevation. But, they were likely picked up by LiDAR measurements to give an artificially high elevation.  Also, there were bushes at both the traditional summit location and the point 440ft west that added error to LiDAR measurements of terrain under the bushes. If there was a natural rock outcrop under any of the bushes, that would likely not have been measured by LiDAR but would count towards elevation.

 

Based on analysis and photos by Ben Loftin, it appeared a boulder at the traditional highpoint location was the tallest point, though it was under a bush and missed by LiDAR measurements and would likely have been part of the old 1928 monument. At the LiDAR-identified highpoint location there appeared to be some rock outcrops sticking up beneath another bush. Those were also missed by LiDAR measurements. So there was considerable uncertainty in the elevations of the highest points. It was thus unclear which of the two locations was the true state highpoint.

Also, given that the ground on top of the mesa is so flat, it would have been very challenging using equipment from 1928 or 1954 to identify the exact highest location when vertical variation is around 1ft or less over large horiztonal distances of over 400ft with no prominent points sticking up. LiDAR is very helpful for identifying general highpoint locations in flat terrrain like this.

I decided to visit both locations, the traditional summit location and the LiDAR-identified location, and use a sight level and a 30x auto level to identify the highest natural rock outcrop in each vicinity. I would then take simultaneous GNSS measurements for at least two hours on the two highpoint locations. Two hours is standard for NGS database inclusion and generally results in errors 0.1ft if there is no vegetation blocking sky view. I would also use the 30x magnification surveying auto level to corroborate the findings by sighting one location from the other.

Friday night I arrived in Denver in the evening and started driving by 11pm. I was trying to pack a lot into my weekend, and the only way to make it work was to not sleep much. I drove straight to the Black Mesa trailhead, packed up, and was hiking up the trail by 6am.

I reached the traditional highpoint location by 7:30am, just before sunrise. Using my sight level I identified the highest rock was the top of a big boulder under the bushes. The boulder was half-covered in white concrete/mortar, as were all the other boulders in the area. These were all definitely part of the 1928 monument.

I mounted the DA2 on a 2.0m antenna rod on top of the tallest boulder and started logging data by 7:45am. I tape measured from the top of the boulder to the ground was a 1.6ft drop.

I then went to the LiDAR-identified highpoint location. With my sight level I identified the highest point was a bedrock outcrop underneath a large bush. I mounted a second identical DA2 on a 2.0m antenna rod and started logging data at 8:15am.

I then returned to the traditional summit location and mounted the 30x auto level on a tripod. I sighted the LiDAR highpoint so that the scope was level with the top of the highest rock. I then sighted all around and verified no rocks in the traditional summit area were higher except the big boulder that I’d mounted the GNSS device on. But that boulder was not natural since it was part of the old monument.

Thus, the auto – level measurements found the LiDAR-identified highpoint was higher than any natural points in the traditional summit area.

After logging GNSS data simultaneously for 2.5 hours I packed up the equipment and headed down around noon, just as many more hikers were hiking up.

Results

I processed the GNSS data with TrimbleRTX and found the LiDAR-identified rock outcrop was at elevation 4,976.3ft +/-0.2ft NAVD88. The ground at the base of the boulder at the traditional highpoint location was 4,974.9ft +/-0.3ft NAVD88. Thus, the LiDAR-identified rock outcrop is the highpoint of Black Mesa and the location of the true state highpoint of Oklahoma. It is at location (36.9320992, -102.9992865).

The auto level measurement gave consistent results, that the LiDAR highpoint location was taller than any point at the traditional summit location except the big boulder. The big boulder was obviously part of the 1928 monument because it was half-covered in old concrete/mortar. Thus, the boulder is not natural, and does not count towards elevation. If that boulder counted, then any human structure on a summit would count towards elevation and people could make mountains be whatever elevation they wanted.

Discussion

The true state highpoint location of Oklahoma is 440ft west of the Black Mesa obelisk. Accuracy-minded highpointers should visit this location to reach the highest point in Oklahoma. I would say climbers who reached the traditional summit location with the obelisk prior to these results being reported should be grandfathered in and can still claim a successful ascent of the Oklahoma state highpoint. But, going forward, future climbers should climb the correct highpoint location to claim reaching the state highpoint.

Data Availability

Raw measurement files can be downloaded at https://github.com/ericgilbertson1/Oklahoma

 

 

© 2026, egilbert@alum.mit.edu. All rights reserved.