Karina Logue, who plays Hank's sister, is in fact Donal Logue's real sister. The pair also played siblings in another FX original series: Sons of Anarchy.
The cap that Hank is wearing at the dock in the last episode is from Camacho's Place; a small restaurant in the Imperial Valley where Donal and Karina Logue grew up.
The year before this show debuted, Michael Raymond-James and Rachel Miner guest starred together on an episode of the TV show "Life" called "Canyon Flowers." Donal Logue was a regular cast member of the show, and all 3 actors shared a scene together.
Terriers refers to a large group of purebred dog breeds. Each & every breed (including Yorkshire Terriers) were bred to chase down and kill some kind of vermin. Because they were bred to work independently, terriers are less attached to people than other comparable dogs. Terriers are notoriously feisty with other dogs; they were bred to hunt solo and thus had little need for sociability. They are bred to dig out burrowed animals, Therefore, you can imagine how this Series was named.