In 2825, a strange but highly skilled unit using SLDF tactics, painted in non-regulation colors and bearing insignia reminiscent of the SLDF's 331st Royal BattleMech Division, a unit that had joined Aleksandr Kerensky's Operation Exodus, attacked four Draconis Combine worlds, stole resources, and left.

The first target was the minor world of Svelvik. The invaders refused to communicate with the Draconis Combine militia, defeated them in battle, took what they wanted, and left the system. They next attacked Trondheim, where the 20th Rasalhague Regulars were stationed. They defeated the numerically superior garrison, again refusing communication.

Coordinator Jinjiro Kurita, upon learning of this new enemy, shifted forces to the Periphery borders of both the Pesht and Rasalhague Military Districts.

At Jarett the DCMS Navy engaged the invaders as they made planetfall, but the appearance of a large number of enemy aerospace fighters won the attackers control of space. They used their aerospace supremacy to continuously attack DCMS mech forces, allowing the invaders to plunder yet another planet.

At Richmond the 331st liberated a camp of political prisoners in addition to seizing the usual goods. All of the camp personnel were shot on the spot and every inmate marched aboard their dropships, never to be seen again. Their motives for doing this were never fully understood.

The stampede of the "Minnesota Tribe" so worried the Coordinator that he ordered a halt in the preparations for the 2nd Succession War. Instead the entire DCMS Navy was tasked with hunting down and destroying the invaders. The final encounter took place over St. John, where warships of the DCMS-N cornered and destroyed the invaders' cruiser "Talleyrand".

No enemy prisoners were taken alive during the campaign: The closest the DCMS came to was an encounter with a lone, almost pristine Lancelot on Trondheim. After a lengthy struggle the DCMS brought down the enemy, but the mechwarrior did not eject. Instead he remained in the cockpit of his fallen mech, where he committed suicide with his service pistol before he could be subdued.

Upon examination the warrior was found to be clad in an advanced version of the SLDF's full body coolant suit. The suit had two patches: One with the numbers "331" stitched on it, which appeared to be a revised version of the insignia of the 331st Royal BattleMech Division "Minnesota". The other of a white Wolverine-like creature with bloodied fangs, which did not match anything on record.

Various theories were put forward as to the origins of the "Minnesota Tribe", but the official version was that these were just another group of pirates with access to a SLDF cache - or possibly the descendants of a splinter group which has left the Exodus.