It's called the Tug Hill, or "the Tug Hill Plateau" if you prefer being hyper-correct about geomorphology. No one says "Tug Hill."
I am a newbie to the region, so please be patient with me, if you find that within you to do so. Thanks.
Anyway, Wiki makes the same mistake. You might edit
the page to make the appropriate correction. That was what led me astray in my nomenclature actually. It also notes that the Tug Hill Plateau is not in fact a plateau at all, and thus I eschewed using the term "plateau," but I digress. Cheers.