The movie playing at the drive-in that young Sam and young Pilar attend is Black Mama White Mama (1973), an in-joke reference to Pilar's mixed parentage.
Sheriff Charlie Wade is armed with a Colt 'New Frontier' revolver, first introduced in 1961 by Colt as an updated version of the old Colt 'Peacemaker'. The events in the film take place in 1957 and 1958.
Mayor Hollis Pogue: Hey, look at all this will ya? Tackle, boat... All just to catch a little ol' fish minding his own business down at the bottom of the lake. Hardly seems worth the effort, does it, Sam?
Coworker:
Your mother's family is Spanish?
Pilar Cruz: Sure, they go back to Cortez. When he rode by, they were squatting in a hut cooking hamsters for dinner.