Tarshan Ring Excavations (TRE) was a mining that operated on and around the planet Tarshan. Some time prior to 27 BBY, TRE approached the cloners of Kamino to produce cloned Humans as miners. The clones the Kaminoans produced were deliberately genetically-engineered to be sterile, though it was found that the clone prototypes displayed much higher rates of mental instability, poor group cohesion, and an inability to adapt and think creatively.