The phrase "come hell or high water" typically means "do whatever needs to be done, no matter the circumstances". It also refers to the "hell or high water clause" in a contract, usually a lease, which states that the payments must continue regardless of any difficulties the paying party may encounter. Both definitions apply to different parts of the plot in this movie.
Toby offers his son a beer. Texas is one of ten states that allows underage minors to consume alcohol in specific locations, such as the privacy of home or in the presence of consenting and supervising family members.
Due to his tight schedule with Star Trek Beyond (2016), Chris Pine was only available for two and a half weeks, so all his scenes had to be shot very rapidly and in sequence to maintain the required level of energy.
Was originally titled "COMANCHERIA" but was changed after a title competition between interns at one of the production companies. The title that won was "HELL OR HIGH WATER". However, in some countries (like Spain) the title is "Comanchería", probably because the pun within the original title does not translate properly.
Anyone living in West Texas can tell instantly that this movie was filmed in New Mexico by noticing nothing more than the road signs. Texas traffic signs are mounted on single round posts. New Mexico road signs are mounted on two u-shaped poles, even the stop signs.
The casino the brothers go in the movie, referred to as the Comanche 66 Casino, is the Twin Arrows Navajo Casino and Resort, almost directly across I40 (old route 66) from the original Route 66 Twin Arrows Trading Post.
At about the 53 minute mark when they are traveling in the car, they pass a closed Shell station. Over the shop in the back you can see three signs that say Shell Travel Plaza. This is the closed Shell truckstop on US54/Bus I-40. They are heading east, on the west side of Tucumcari NM. This road is also the original Route 66.
Dale Dickey and Kevin Rankin, who do not share scenes in this film, also appeared in Breaking Bad (2008) where they also did not share scenes. Both works were filmed in the state of New Mexico. They also appeared together in Claws (2017), where Dickey played the aunt of Rankin.
Fans can make two, unintentional connections to petroleum companies Phillips 66 and Texaco. First, actor Jeff Bridges was the title character in Starman (1984). Texaco's logo is a star, and "Hell or High Water" takes place in TX. Bridges wears one for his badge, as well. This motion picture was also filmed on location along Route 66.