Navigating The Ravine is trickier than other transition zones. Going from Mystery Lake to Coastal Highway, the player will have to balance across a fallen tree trunk, then follow a long, winding track through a tunnel and then cross a narrow and rickety train bridge before finally reaching a final tunnel through to Coastal Highway.
Ravine Basin Edit
Since version 0.321 there is a small chance a rope will spawn (together with some other loot) in one of the hanging train wagons which can be deployed near the aforementioned fallen tree trunk to go to the bottom area, called Ravine Basin. One can find a distress pistol, some flare shells, a human corpse, a deer carcass, rabbits, cat tail stalks, a cairn, some other random loot and a full sheltered cave with an improvised bed inside.
The rope climb back is a very long one. Using coffee or sleeping in the improvised bed or a bedroll will help prevent the player from becoming stranded in the Ravine Basin due to exhaustion. The climb isn't possible unless one stops at the ledge (accessible when 2/3rds of the climb is completed) to catch one's breath by looking to the right and clicking the interact button (default left click).
Alternatively one can use an emergency stim, but the player will be fully exhausted afterwards.