He waits until they return to their car, then leans toward the window:
[Chris and Reagan babble excuses.]
SHERIFF: Just kidding! This is the side of the road. Nobody's buried here.
[Chris and Reagan laugh in relief.]
SHERIFF: But you're still getting a ticket for public urination.
IMDB says the character's name is Officer Littlejohn. He's played by actor Miguel Nájera, who describes himself as Chicano/Native.
This is a small but good scene. It shows how you can integrate Indians into everyday life. We get a bit of Native lore, a bit of Native humor--but not at the expense of the Indian--and a visual cue.
But it's not forced. The sheriff isn't even identified as an Indian. The subtle message is that Indians still exist and are just regular people.
For more on Up All Night, see Thanksgiving in Up All Night and Pete Littlebear in Up All Night.