“Skookumchuck” describes turbulent water or rapids, such as those in a steam or river. It’s not widely used anymore, but most folks in the PNW are at least familiar with it (sometimes from the names of places or people), and it’s the only place you’ll hear the term in America. (For the record, it is also used in British Columbia.)
Shazam, Pilgrims! Ah’s always reckon’d it be de sound yer makes after yer ett too much rancid Spam an’ Tang.