Specialist officers have been combing the scene on the Jarrahdale State Forest south-east of the Western Australian capital.
The lady was thrown from the quad bike, which she was a passenger on, about 5pm yesterday.
Emergency providers rushed to the agricultural space to assist however she died on the scene.
WA Premier Rodger Cook dinner mentioned police have been investigating.
“She was a passenger on the quad bike. The quad bike rolled and these terrible set of circumstances occurred,” he mentioned.
The 34-year-man behind the wheel was taken to Armadale Hospital for minor injures and an alcohol evaluation.
No expenses have been laid.
Police now need bike riders, hikers and members of the general public who could have seen the duo earlier than the crash to get in contact with Crime Stoppers to assist investigators piece collectively the tragedy.
To date this 12 months eight Australians have been killed on quad bikes.
Cook dinner warned individuals to watch out.
“These quad bikes and different instruments are nice out of doors journey equipment however they have to be handled with a substantial amount of respect and care,” he mentioned.
New figures reveal a spike within the variety of lethal crashes on WA roads.
The state’s street fatality charges are properly above the nationwide common, hovering by 12 per cent in comparison with final 12 months, a rise solely matched by Victoria — main the nation — with numbers up by 13 %.
By Sunday, 81 lives had been misplaced on WA roads.