Helms Ferry: One of the Last Working Car Ferries In Tennessee UNION COUNTY, TN (WKNO) - If you travel through northeast Tennessee, through Maynardville and into the rolling pastures of Union County, you may just stumble upon something that takes you back to another time. It's the Helms ferryboat and it's one of the last working car ferries in Tennessee. The Union County Road Department has operated the ferry for more than 20 years at no cost to its riders. Matt Shafer Powell recently spent some time on the ferry with one of its captains. © Copyright 2009, WKNO