The West Coast’s Largest Rock Festival returns To Discovery Park October 10-13, 2024. Sacramento, Calif.- Aftershock 2024 returns to Discovery Park in Sacramento, CA October 10-13 for its 12th year with its biggest lineup yet. The 4-day destination festival will feature the only U.S. festival play for Iron Maiden, the exclusive West Coast performance for Slayer-one of only three shows in nearly 5 years-Slipknot as one of the number one requested bands, and the first Aftershock appearance for Mötley Crüe, making it an event not to be missed!