In Fallout: New Vegas, you meet many ranger NPCs, among which is Ranger Andy in Novac who seems to suggest that it's possible for the Courier to become one. I came to the conclusion of a possibility from a question the Courier asks Andy:
How does one become a Ranger?
to which Andy replies something along the lines of
Yew need to be the meanest, toughest, takenocrapiest sonuvabitch this side of the Jawjuh, hoo-wee!
Is there a way to become a Ranger, or am I just interpreting the dialogue wrong?