DeMuri said he knew they got the boulder right when [rock climber and biopic subject Aron] Ralston visited the Sugar House set. He looked at the boulder and was surprised that it was a copy. “He said, ‘You see these indentations right here? This is what I chipped away with my multitool.’ Danny looked at me and winked. I knew we got it right.”

That fidelity extended to the costume design, Larlarb said. She tracked down the manufacturer of Ralston’s shoes and even outfitted Franco with the same brand of headlamp.

She made one small change, finding a different Phish T-shirt (Ralston’s favorite band) because the band’s name was too prominent on the one he actually wore during his accident. “If I had used that shirt, we would have read the word ‘Phish’ for 90 minutes, and that would have been incredibly detracting,” Larlarb said. “I went through the Phish back catalog of concert T-shirts, and I found one that was a little more abstract, but in keeping with what he wore.”