(Corvallis, OR)  --  Police are seeking help in their search for a missing Corvallis teen.  Police say 16-year-old Ava Carey disappeared last Thursday after leaving her home to go to a nearby park.  She was last seen around 6:00 that night with her skateboard in the seven-hundred-block of Northeast Conifer Boulevard.  She's described as five-foot-six and 107 pounds with short auburn hair that's shaved on one side.