The text below is quoted from the book "The Housatonic - Puritan River", by Chard Powers Smith, published in 1946.

"Whatever may have been the prehistory of the original Indians of Berkshire County, Massachusetts, which contains the whole of the Upper Valley, they yet performed the service of establishing the principal and most enduring place name in the valley.

When they immigrated, the came in from the west over the mountains, and the place where they established became Wussi-adene-uk, the “Beyond-the-Mountain-Place,” the country beyond the mountains.

The Indians accented the first syllable, and, allowing for the elision that would have occurred at the outset, the original pronunciation would have been close to Wusadenuk or Wusatenuk.

Through innumerable spellings by the whites, including Westenhook, Westonock, Hooestennuc, Awoostenok, Ansotunnoog, Ousetonuck, Ousatunick, Housatunack, House of Tunnuch (!), Housatonac, and with the transference of accent to the third syllable, it has reached its modern form, Housatonic.

As late as 1859, Princess Mahwee, the last pureblooded survivor of the Scatacooks in Kent, said that it should be pronounced Housetenuc.

Like Potatuck, the place name was transferred to numerous features of the region it described. The traveler in 1694 said the place where he crossed the river - otherwise identified as the Great Wigwam - was called “Ousetonuck.” Thus the place name was attached to the principal village in that place.

And, at the coming of the whites, the Indians of the Upper Valley were known as the Housetonucks, the people who lived in the place beyond the mountains.

It was not until the eighteenth century that the name flowed downstream to become generic for the whole River, replacing “Potatuck,” “the Great River,” and the other Indian and English names that had been used in the Lower Valley."

An overview map of the entire Housatonic River Basin is available.