Growing up in Arkansas, I could spot the Arkansas Highway and Transportation Department's shade of orange anywhere. By the look of it, the vessel has been there for a while. Looking at the Google Maps image below it was on the west bank of the river until the past year. I discovered it in May 2013 on the east bank.
It's located across from the Martin Access on the White River. (The picture opens a Google Maps link)
If you know where this ferry came from or who owns it, I'm curious! Please leave a comment below.