It was hikers walking this border route who warned the Spanish authorities after making the macabre discovery last week.
A piece of human skull "bearing remains of hair" was "near a hiking trail at Port de la Gléré", along with bones "of animal origin".
Finally, it was established that the remains were on the French side of the relief.
The bones were sent for DNA expertise to the Toulouse forensic science laboratory, and the results are not yet known.
The presence of both human and animal bones suggests that they “were probably moved by an animal, because the area had been combed through by the gendarmes”.
Last sign of life in November 2020
Esther Dingley had not given any sign of life since a WhatsApp message sent on November 22, 2020. The young woman had reached Spain by car at the end of October, before the second confinement decided by the French authorities. She wanted to benefit from more flexible traffic conditions in Spain for a mountain hike. She had to make a loop around the Pic de Safeguard (at an altitude of 2,738 m) "between Spain (where her car was parked) and France while spending a night at the refuge of (Port de) Vénasque", had specified the investigators.
It was his companion, Dan Colegate, who remained in France, who had given the alert to the Spanish authorities.
Significant research assets had been deployed on both sides of the border.
The couple had been traveling across Europe in motorhomes for six years, according to a BBC portrayal of them.
He had told the BBC that he had stayed to guard a house in a Gascony vineyard while his companion had taken their camper van for her trip.
Investigators favor the accidental cause, while Dan Colegate leans for a criminal act in another BBC article.
The Saint-Gaudens (Haute-Garonne) public prosecutor's office entrusted the investigation of this disappearance to the gendarmes of the Saint-Gaudens Research Brigade and the Toulouse Research Section.