A major emergency service response was called to Friarton Quarry in Perth before one teenage boy was airlifted to hospital.
A 14-year-old suffered “serious injuries” after a crash involving a quad bike on Saturday afternoon.
A 34-year-old man was also taken from the scene by ambulance, with a spokesman for Police Scotland confirming an investigation has now been launched.
Several emergency services vehicles – including two fire engines, were at the scene during the incident, which was reported just after 2pm.
A spokesman for the force added: “Officers were called around 2.25pm on Saturday, June 12, 2021, following a crash involving a quad bike at Friarton Quarry in Perth.
“A 14-year-old boy sustained serious injuries and was taken to Ninewells Hospital by helimed and a 34-year-old man was taken to Ninewells Hospital by ambulance.
“Inquiries into the incident are ongoing.”