Although Mending the Line sees war veterans Ike Fletcher and John Colter bonding over their shared love for fly fishing as a means of dealing with their Post-War trauma, it begs whether its events are based on a true story. Mending the Line is one of Brian Cox's best movies, as it sees him in a mentorship role to the film's younger protagonist John, played by Sinqua Walls. John is a wounded Afghanistan veteran who takes up residence in Montana, whereupon he befriends Cox's Ike at a Veteran's Affairs facility, and learns how to cope with his trauma via fly fishing.

https://screenrant.com/mending-the-line-true-story-inspiration-explained/