Who else thought the characters began experiencing side effects of some sort of chemical weapon being tested by the military? It would explain what the regular bangs in the distance were.
Delirium, audio, visual & tactile hallucinations, sensory overload, paranoia, fear, confusion and disorientation.
All could be caused from accidental exposure to a
chemical weapon, maybe the mkultra experiments never stopped and this is the current RND.
The US military use vast empty deserts as test ranges so the group ending up close/downwind to testing is possible.
Think about the snakes!
That's my 2 cents anyway
Edit: I kind of jumped the gun reviewing a movie before it finished 😂