A Harvester rig was a large agricultural vehicle used on the planet Prairie to harvest the vast areas of crops. Harvesters would collect grain from the plains for months at a time before delivering it to settlements such as Silotown.

Each rig supported at least a small crew and were equipped with a number of small vehicles called skimmers for short range transport away from the rig and for use in emergencies such as putting out a fire. Otherwise rigs were only equipped with minimal technology, such as short range comm units to contact other rigs.

Two known rigs were the Rostok and the Sholakov. (EV comic: "The Flat, Gold Forever")