This site is not a new discovery; it’s mentioned briefly near the end of a Marfa Public Radio writeup, and also mentioned in “Exploring Organ Mountains-Desert Peaks National Monument”, by Devon Fletcher and David Soules.
The site coordinates are 32.471950, -106.768017 ( 32°28’19.0"N 106°46’04.9"W), and it’s part of the Chihuahuan Desert Nature Park. However, there is no trail and the site is not marked in any way. You just have to find it: drive to the upper parking lot, walk up the ungated road leading west for a bit over a mile, and look uphill. The biggest boulder is your destination.
In the pictures below, the big rock is seen from above, and the road is beyond the rock and above the lower flats. In Pleistocene times the distant alkali flat would have been a shallow marshy lake and the landscape much more verdant. Other upright boulders in the area show rubs too, though I’ve not found any as impressive as the one pictured. The detail photo shows the difference between the rubbed surface and the rock where a chip has come off.
Any idea what kind of animal rubbed against it? If memory serves correctly, the Pleistocene era saw the gradual formation of the land bridge between North and South America, before which there could’ve been some hefties in the plains of the north? One of the big Bison ancestors maybe?
@anthonywalton: One of the lines of evidence for animals causing the polished spots on the boulders was the observation of African elephants rubbing on similarly polished boulders. So it seems reasonable that elephant relatives – mammoths, mastodons, and gomphotheres – might be responsible for the North American rubs. Certainly Bison latifrons, the Giant Bison, may also be responsible (though the species went extinct in N.A. quite a bit earlier than mammoths and mastodons). Ground sloths? Cave bears?
I haven’t read deeply into the research on this topic. I keep intending to…
