245 collectibles in Days Gone.
Weaver - "Look to the Stars"
A letter to Lieutenant Weaver from a chemistry professor, tied to his work on Wizard Island in Crater Lake. It unlocks on its own through the story.
Wild Bergamot
Wild Bergamot is a mint-like herb in the Herbology set, entry 23 of 33, and it grows in the Cascade region. Its main use is selling at a camp kitchen for credits and Trust.
Wood Lily
Wood Lily is a red or orange lily in the Herbology set, entry 24 of 33, and it grows in the Cascade region. Its main use is selling at a camp kitchen for credits and Trust.
Yeast
Yeast is Sarah's lab note 2 of 6, a short audio log she records on Wizard Island. You get it automatically during the story mission I Know Things Are Strange, so it can't be missed.
Yesterday (camp song)
"Yesterday" is song 1 of 6 played by the guitarist at Iron Mike's Camp in Lost Lake. He turns up at random in the gazebo behind the bounty collector.