There may not be a "Big Four" metal tour this summer, but MEGADETH won't be sitting around at home.

They're one of the headliners for this year's Rockstar Energy Drink Mayhem Festival.

The other two are GODSMACK and DISTURBED . . . and the bill also features Machine Head, In FLames and Trivium, among others.

The tour includes 26 dates, beginning July 9th in San Bernardino, California.

For all the details, hit up RockstarMayhemFest.com.