Fix the cable car: A trunk blocks the cable car. Follow the sandy path to reach the pylon and fix it. That's the only way to Turtle Rock.
The quest "Fix the Cable Car" is started when the player picks up the Note attached to one of the cable cars, which are located East of the northern Canyon entrance. There is a repairable Direction Sign along the way that, when fixed, will point the player in the direction of Turtle Rock. Follow that path to find the cable car. The note informs the player the the cable car is out of service due to a fallen trunk on the pylon. The quest item "Note" will then be added to the player's inventory, listed under "Things I have" in the notebook.
In order to complete this quest, the player must follow the, somewhat hidden, path leading East all the way to the shoreline, then South until the path does a U-turn, heading North up the cliff. Continue following the path heading West along the cliff's edge, being careful not to fall off. The player will need to jump across a gap (or walk along the log, if they didn't collect it), and continue around the corner and back South again, until they reach the pylon . Jump onto the pylon and collect the trunk. The quest will be marked as completed but the cable car will not begin operating until the player enters the car for the first time, as which point it will begin its endless loop.
It is possible to complete this quest before reading the note from the cable car guy. If the player removes the tree trunk from the pylon, the quest will be added and instantly marked complete in the players notebook. However, the player will still need to read the note in order for the cable car to begin operating.