The Trasse Proving Grounds were a secret Imperial factory complex on Trasse that constructed All Terrain Armored Transports. As part of the manufacturing process, the AT-ATs were tested in outdoor firing ranges by firing on prisoners. There were two of these ranges, one for infantry and one for armor.

After his defection to the Rebel Alliance, Brenn Tantor used the knowledge of fellow defector Beri Tulon, who had been stationed at the facility, to raid it and steal an AT-AT walker.