Beyond the evasion that Henry is doing by going to Two Forks because of his wife's alzheimer, it's the parallel to the story between the father and the child what builds the layers for me. The kid built his own fortress in the mountains to not fall under his father's control and to have a place where he could plan out his dreams, a little "fantasy world" as Henry puts it.

The father took it to an extreme, and his cowardice and not handling his responsability made him evade the rest of the world in a demented state of mind, hiding away in the place he wanted to share to his son without being able to connect on the same wavelenght, just like Henry wouldn't be able to reach out to Julia anymore. Apart from the practical use of the information to frame the two protagonists, I wonder if in his little refuge he also was trying to figure out how Henry and Delilah were on a similar wavelenght not just from the walkie talkie frequency, but also in human connection, the kind that he couldn't have with his son.