Quad bike crash

The woman was located by a passer-by about 8.15am.

Ambulance Victoria advanced life support paramedics, mobile intensive care ambulance paramedics and the air ambulance helicopter treated the woman at the scene.

An Ambulance Victoria spokesperson said the woman in her 30s was flown to The Alfred hospital by air ambulance in a critical condition with upper body injuries.

An investigation into the incident is under way.

Any witnesses, or anyone with vision or information is urged to contact Crime Stoppers on 1800 333 000 or anonymously online at crimestoppersvic.com.au