There are ten clues:
- The blood on the railway
- The footprint near the railway
- The blood on the fence near the railway
- The pollen near the tent
- The blood on Jeremy Bowles' leg
- The orchid on Jeremy Bowles' chest
- The Mud on Jeremy Boweles' face
- The origami figure in Jeremy Bowles' hand
- The fingerprint of Jeremy Bowles (You must check his hand twice to get the trophy)
- The footprint near the highway
- The tire tracks near the highway
To find the last two clues you have to climb a hill. Start near the blood on the fence.
When you have found everything, Jayden will say "Well, I've seen all there is to see."
The Wikia provided the complete list.