A Rover Runs Through It - S9-E1
Continuity mistake: At the beginning of the episode, after Peggy's mother calls, Hank says "What's it been? Twenty years?" But they spoke with Peggy's mother during the events of the episode "Happy Hanks Giving." Hank spoke to her on the phone, Peggy shouted at the phone, and Hank commented on Mrs. Platter not approving of propane.
Answer: Jeffrey Boomhauer is a Texas Ranger as can be seen in the final episode at the end when he sets his wallet down, it flips open revealing a Texas Ranger badge.