A hiker saw/heard Josh fly over quite close to the ground but didn’t think anything of it as its common in that area. It wasn’t until the hiker reached the top of the valley that he looked down and saw Josh’s body in the shallow riverbed/stream.
He then notified police and the helicopter rescue team came to retrieve him.

Judging from where he impacted, he was flying a line requiring very good glide and early commitment. He must have known he had gotten himself into a bad spot as he had pulled his parachute.