From Halopedia, the Halo wiki
During the Fall of Reach in 2552, the UNSC Pillar of Autumn docked at the ship-breaking yards nearby Törött, to receive a fragment of the AI Cortana from the three remaining members of NOBLE Team, Carter-A259, Emile-A239 and Noble Six, who were tasked with ferrying it to the ship from SWORD Base. NOBLE arrived at the ship-breaking yards on August 30.
At some point while the Autumn was docked, Pelican Bravo 001 became lost and was directed by the radio operator Golden Arrow to change its heading to south-southwest and fly straight over the tree tops and land in the woodland near Mount Törött. Unbeknownst to Golden Arrow, Bravo 001 was supposed to be transporting SPARTAN-II Red Team to the Asźod ship breaking yards to rendezvous with the Pillar of Autumn.
After making their way through Covenant-occupied territory to reach the ship, and losing Carter on the way, Noble Six and Emile delivered the fragment of Cortana to Jacob Keyes, the captain of the ship. However, Emile was killed by a Sangheili Zealot moments after, and Six was forced to remain behind to cover the ship's escape from an approaching CCS-class battlecruiser with a nearby Mark 2488 Onager emplacement. He was successful, and the ship managed to break atmosphere unscathed. Now alone, without any support or possibility of evacuation, Six was eventually overwhelmed by Covenant forces and killed near the foot of Mount Törött.
In the aftermath of the Human-Covenant War, Unified Earth Government marked Reach as a priority target for reterraforming and recolonisation. The planet made a significant ecological recovery, and the area surrounding Törött became verdant and lush with vegetation. By 2589, the area was habitable again and an unidentified colony ship landed in Asźod, at the base of the mountain, and commenced recolonization of the area. At this point, the mountain was covered in snow.
While Mount Törött is never explicitly named in Halo: Reach, it can be inferred via several contextual clues given in the radio conversation on the multiplayer map Breakpoint. In the conversation, Golden Arrow advises Bravo 001 to head for Mount Törött to go to the "Boneyard". The multiplayer map Boneyard is set in the Aszod shibreaking yards, which are overlooked by the "broken mountain" prominently featured in Halo: Reach.
Additionally, "Törött" is a word in Hungarian, meaning 'broken' - which is a fitting name for the mountain. Altogether, it can be reasonably inferred that the broken mountain heavily emphasised is in fact Mount Törött as named in the radio transcript.
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