Lost black backpack with a red logo containing personal items near the picnic area at Mansfield Park.

I lost my black backpack with a striking red logo at the Mansfield park last Saturday afternoon. It has several pockets and contains some personal items, including a blue water bottle and a few study materials. I believe I left it near the picnic area while I was having lunch with friends. I'm really hoping to get it back as it has some important stuff inside.