What item's are essential to bring into the Quetico?
I know you must bring a trowel.
What about a fire grate if I want to cook over the fire or should I just plan to use my stove?
Anything else I need to bring that you wouldn't necessarily need in the BWCA?

Those are the only 2 items not neccesary in the BW that are in the Q that I can think of......besides no bait and barbless hooks.

You're supposed to have a bailer and whistle.

You might want to bring some bug juice.

GULP!

Trowel as noted and a fire grate. I use a SS folding model, others assure me that the perfect Q fire rings will work with a round Weber style grate.

I quit hauling firegrates years ago. Many campsites have them stashed in the weeds. If you can't find one, flat rocks work great (grate).

We've gone years without using a grate, as we always use a stove for cooking. To me a chair (therm-a-rester) is a much better addition to the trip. The older I get, the more some items seem essential or represent such a dramatic improvement (headlight, anything made of fleece, Keens, collapsable water jug)that I would really miss them.