Continuity mistake: In the scene where the boys are changing into all their hunting gear on the side of the road, keep an eye on Christopher Walken. In a wide shot, he's pulling on a dark green sweater. There's a quick shot of De Niro, then back to the wide shot, in which Walken is again pulling on the dark green sweater.
Trivia: During the helicopter stunt, the runners caught on the ropes of the suspension bridge and as the helicopter rose, it threatened to seriously injure both Robert De Niro and John Savage. The actors gestured and yelled furiously to the crew in the helicopter to warn them. Footage of this is included in the film.