Tomorrow morning, the annual Treasure Island Music Festival announces their much-anticipated lineup. But today, TIMF offers fans a hint for what's to come: Animal Collective. TIMF has been releasing subtle clues via Instagram over the holiday weekend; today they featured the hypnotic cover art for Merriweather Post Pavilion.

Also probably on the 2013 bill? Poolside, Palma Violets, Phantogram, and Lord Huron.

SFist will be announcing the full TIFM lineup on Tuesday morning.