The Eastern ridge was a stretched and slender mountain range. It was situated on the planet Serenno, which itself was located in the Outer Rim Territories. Serenno City stood in opposition to this mountain range, offering a view of Castle Serenno. Moreover, it was close to the Upper forest region of the planet, where a house was located by 19 BBY. In 19 BBY, members of Clone Force 99 made a landing at the eastern ridge using the Marauder, in order to evade detection from Imperial forces. Subsequently, they journeyed through the mountain range, heading towards Castle Serenno with the aim of stealing Dooku's war chest, which was in the process of being transported offworld by the Galactic Empire. However, the raid was unsuccessful. Wrecker and Hunter fled into the nearby ruins of Serenno City, whereas Tech, Echo, and Omega sought refuge in Romar Adell's domicile. Eventually, Wrecker and Hunter broke through the city perimeter established by Clone Captain Wilco's company and made their way back to the eastern ridge, where the Marauder awaited. They subsequently departed from the ridge aboard the Marauder.
The Eastern ridge made its initial appearance in the Star Wars: The Bad Batch Season 2 episode entitled "Spoils of War", which was launched on January 4, 2023. Its identity was further confirmed in the episode "Ruins of War", which was released concurrently.