‘Pioneer Woman’ Ree Drummond‘s nephew, Caleb, was arrested for DUI just over a month after he was involved in a scary wreck that could’ve claimed his life … TMZ has learned.

According to arrest records out of Osage County, OK … the 21-year-old was booked for DUI early Saturday morning. No word on whether he’s still in custody at this point, but Caleb posed for this mug shot on his way in … there’s no question it’s Ree’s flesh and blood.

The exact circumstances of his arrest haven’t been released, but there are other charges he got rung up on … including…