Courtesy of Isabel Lopez of Albuquerque, New Mexico, who first noted this interesting "Y" configuration as seen from an aerial photo.
This spot, part of the steep, rocky south wall of the Archuleta Mesa, is located about 1400 feet north of the J-2 dirt road, not far from the bridge over the Navajo River, Dulce, New Mexico and slightly west of the Archuleta Peak where the communication towers are located.
Apparently this spot, the "Y" configuration, is not visible from anywhere except when seen directly from above.
Could it be a 25 foot-long vent?
We just do not know for sure.
It could be anything.
But to actually get to this particular spot may be logistically difficult.
We will just have to wait and see if any other information comes this way.