Prerequisites: Max out Forrest's level 1 friendship
One of Moonbury's two rangers, Forrest spends the majority of his days combing the wilderness for materials requested by the townspeople, as well as keeping anyone who enters Meadow Range out of trouble. Forrest is almost always in one of two places: Near the Ranger Post, which is just outside Meadow Range, or at his house, which is just south of the Ranger Post. You'll likely befriend Forrest and Bubble at the same time, as the two of them hang out together constantly.
Sufficiently befriend Forrest and he'll post a note on the Bulletin Boards around town, requesting that you come see him. You can trigger the cut scene with Forrest from 7:00 to 15:00 on any day of the week by approaching the Ranger Post.