An interface jig for removably securing a portable auger to a vehicle includes a carriage guide assembly, a sliding carriage assembly and a receiver assembly. The carriage guide assembly includes a vertical support having an upper portion and a bottom portion. A hitch adapter is affixed to the bottom portion to secure the carriage guide assembly to a vehicle hitch. The sliding carriage assembly includes a horizontal member having a first end opposite a second end. The first end is affixed to a vertical member that slides along the vertical support between the upper portion and the lower portion of the carriage guide. The receiver assembly is attached to the second end of the sliding carriage assembly.