A man has died after falling down a steep gorge at a popular Adelaide hiking trail.

Witnesses report that a man was hiking with a woman in Morialta National Park when he fell into a ravine near Deep View Lookout shortly before 12:30 pm.

Witnesses who first raised the alarm say the woman approached them after the horrific incident calling for help.

“She mentioned she had just met this man in class and it was their first time going out together when this accident occurred,” witness Aliman Tazudin recounted.

The woman claimed the man jumped over a barrier along the walking trail to pick up a littered plastic bottle before he fell.

“She said her friend was against littering and when he noticed a bottle over the fence, he attempted to retrieve it, and then he fell,” Tazudin continued.

The conservation park was temporarily closed for several hours as emergency teams conducted a complex rescue operation in the tough terrain.

“While passing by one of the lookouts, we noticed CFS crews in the area, followed by multiple firetrucks and police cars,” park visitor William White observed.

The man died at the scene.

Police will investigate the circumstances surrounding the man’s death.