A 16-year-old boy has been found dead in a Blue Mountains creek after losing touch with his companion on a camping trip.

Police were told he and a 17-year-old boy travelled on Tuesday to the train station in Leura, about 80 kilometres west of Sydney, before setting off for Mount Hay on foot.

It was supposed to be a three-day camping trip but about 5.45pm on Wednesday the older boy activated his personal locator beacon when they became separated.

Blue Mountains Rescue Squad, PolAir, NSW Ambulance paramedics, and the TOLL Rescue Helicopter all joined in a land and air search. (Toll Ambulance Rescue)

The Blue Mountains Rescue Squad, PolAir, NSW Ambulance paramedics, and the TOLL Rescue Helicopter all joined in a land and air search.

They winched the 17-year-old to safety from the Acacia Flat campground but couldn’t find the 16-year-old.

He was eventually found dead in a creek relatively nearby in Blue Gum Forest, about 1pm yesterday.

A post-mortem still needs to be carried out to determine how the boy died, and a report will be prepared for the coroner.

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