Looking at the picture, it looks pretty close to the bed rails.
I could see someone in my are driving on of those!
I am a Retired U.S. Merchant Marine Chief Engineer
05 Chevy 2500 4x4 D/A with Helper Springs and Air Ride Air Bags
06 R-Vision RW3360 Fifth Wheel Toy Hauler
97 FLTCI converted into a Roadsmith Trike by The Trike Shop of Daytona