Might depend on how picky you are.
In fact, there's plenty of food sold both in the territory and beyond, and there is a choice, so bringing your own stuff isn't such a good idea [we made such a mistake the first time
] ....unless you have to keep to a diet or something like that.
As for me personally, I loved the fish that the local folks offer.... yummy
...my DH was more impressed by elk steaks (those were sold in the festival area in 2005), but I was actually left unimpressed by them [too much onions gave me heartburns thereafter
]
BTW, the prices are really friendly there.
Oh, and before I forget it - the only exception to the above is coffee. Mostly thin as I don't know what (actually coffee-flavoured water from the POV of a strong-coffee-freak like me).