The medical clinic building is actually an Ironworkers union hall.
In order to get the cows to react to a fictional "flying creature", there was a wrangler off screen making dog noises.
The Copeland family motorhome is actually a pair of duplicate motorhomes. One was used primarily for interior shots, while the other was used mainly for exterior and traveling shots.
The poisoned whisky that Josh tricks the looters into drinking is actually just water plus food coloring.
Karen's necklace is inspired by the U.S. military's Air Assault badge. Though she is no longer in the military, the badge represents a significant time in her life and is something she keeps close to her heart.