Start at the Pawsitively Green Center. Click on the big round recycling sign above the door to the center to get started on the Nature Walk. Items that can be composted can be found all around BuildaBearVille.
The locations are different for everyone and different each time you log in. You can repeat this quest once a day,by finding 5 items you are awarded 200 bear bills

Now when you do enviromental walk if you are not wearing a ride you get to carry a cool new green recyling basket just during the game