Native American Place Names of Massachusetts:

Nonotuck, Northampton, Hampshire. “In the middle of the river.” Vide Norwottock.

Nonotuck Mountain, Northampton, Hampshire. This word occurs in many forms.
Nonotucke, same asd Nonotuck, Norwottock, Noatucke etc.

Norwootuck, Hadley, Hampshire. Mass. Bay Col. Rec. Vol. 3, 415, 430.
Norwottock, Hadley, Hampshire Co. “Far away land,” H. A. Wright, or “In the middle of the river.” Judd.
Norwottock Mountain, Hampden Co.

Judd is the work you're reading. Wright is here and isn't happy with Judd's version.

I have always heard the rail trail pronounced as “Nor-WAW-tik,” for whatever that’s worth.

Welcome to the Pioneer Valley! (I'm a resident myself.)

You might also find Nancy Pick's article "The Meaning of Massachusetts...and Other Indian Place Names" interesting. It's in the Summer 2007 issue of New England Watershed magazine, published in Hatfield.

This (former) local pronounces it "nor-WAH-tuck" too. It is the name of the distinctively sloped mountain on one side of the Notch (rte. 116) in the Holyoke Range. I didn't know that it was also a name for the whole valley. Welcome to Norwottuck, aka. the Happy Valley, Languagehat! 'Tis a wonderful place, and I miss it.

Incidentally, that John Pynchon is an ancest0r of author Thomas. Here and there in his oevre there are references to his illustrious Pioneer Valley forebears, for example, William Pynchon, the founder of Springfield, Mass., becomes William Slothrop in Gravity's Rainbow. Do you suppose this has anything to do with Pynchon's guest appearance on the Simpsons of Springfield, USA?

BTW, Jeremy over at PhiloBiblos has been trying to persuade Applewood Books, who did that nice little dictionary, to reprint Eliot's Indian Bible. They have reprints of his Indian Grammar Begun and Roger Williams' Key into the Language of America. I wish someone would.