"Mendocino County Line" is a song written by Matt Serletic and Bernie Taupin, and recorded as a duet by American country music artists Willie Nelson and Lee Ann Womack. It was released in January 2002 as the lead-off single from Nelson's album The Great Divide. It was a Top 40 hit on the U.S. country chart, peaking at number 22. It was Nelson's first Top 40 hit on that chart since "Ain't Necessarily So" in 1990. It won the Grammy Award for Best Country Collaboration.