Spanish rescue teams are searching for an American hiker who has been missing in the Pyrenees for eight days.

Specialist mountain rescue teams and helicopters from the Air Service are searching for Cole Henderson, 27, in the Ordesa y Monte Perdido national park in northern Spain, the Guardia Civil told CNN on Wednesday.

Henderson was last heard from on July 9, said Henderson’s friend Max Senoff in a Facebook post published Tuesday.

He sent a text saying that he had parked his car, turned his phone on airplane mode and was beginning his hike. He has not been heard from since.

Henderson was reported missing on July 14, after he missed his flight home to the Netherlands on July 12, said the Guardia Civil.