Is Simply Pine discontinued? Why? Where can I purchase it? 

Yes, unfortunately we recently made the difficult decision to discontinue all Simply Pine cat litters. With the current economic conditions and raw material prices continuing to rise, we have decided to focus all our efforts and resources on our rapidly growing premium okocat litter brand. We deeply apologize for the inconvenience. We do not have an alternative non-clumping wood litter to offer you at this time, but we do have a non-clumping PAPER cat litter that's perfect for cats or homes with allergies >>> okocat Dust Free Non-Clumping Paper Pellet Cat Litter (healthy-pet.com​) or try one of our okocat wood clumping litters instead.