The first geological discussion of a large lake in the Connecticut River valley came from the personal journal of the President of Amherst College in 1822. In this volume President Timothy Dwight describes an Indian legend told to him by the elders of Northampton, MA. This legend tells of a time in the past when the river valley north of the Holyoke Range was occupied by a large lake.

The Pocumtuck Indian tribe from near Deerfield, MA, has a similar legend describing a large lake in the Connecticut River valley asociated with the myth of a giant beaver. In their legend a large beaver lived in this lake and occasionally came ashore to eat people. The Pocumtuck people didn't like this so they called on Hobomock, a spirit giant, to kill the Beaver. Hobomock chased the giant beaver into the lake and hit it on the back of the neck with a large stick. This killed the giant beaver causing it to sink to the bottom of the lake and turn to stone. According to the Pocumtuck legend, the giant beaver can still be seen today.

Its head is Mt. Sugar Loaf and its shoulders are North Sugar Loaf Mt. Its body stretches the length of the Pocumtuck Range to the north with its tail at Cheapside. The large divot between Mt. Sugar Loaf and North Sugar Loaf Mt is the location where Hobomock struck the giant beaver. Four historical accounts of this legend are reported below.

The Great Beaver (Field, 1870-1879)

"The Great Beaver, whose pond flowed over the whole basin of Mt. Tom, made havoc among the fish and when these failed he would come ashore and devour Indians. A pow-wow was held and Hobomock raised, who came to their relief. With a great stake in hand, he waded the river until he found the beaver, and so hotly chased him that he sought to escape by digging into the ground. Hobomock saw his plan and his whereabouts, and with his great stake jammed the beaver's head off. The earth over the beaver's head we call Sugarloaf, his body lies just to the north of it."

The Pocumtuck Range (Sheldon, 1983)

"The Pocumtuck range, according to Indian tradition, is only the petrified body of a huge beaver, which used to disport itself here in a pond of corresponding dimensions. This animal, by continuing depredations on the shores, had offended Hobomuck, who at length determined to kill it. Accordingly, armed with a trunk of an enormous oak, he waded into the water and attacked the monster. After a desperate contest, the beaver was dispatched by a blow across the neck with the ponderous cudgel. The carcass sank to the bottom of the pond and turned to stone. Should any skeptic doubt the truth of this tradition he is referred to the beaver itself. Wequamps (Mt Sugar Loaf) is the head, north of which the bent neck shows where fell the fatal stroke; North Sugar Loaf, the shoulders, rising to Pocumtuck Rock the back, whence it tapers off to the tail and Cheapside. All this is now as plainly to be seen by an observer from the West Mountain as it was the day this big beaver pond was drained off."

Wequamps (Abbott, 1907)

"Many, many suns in the past, ere the wigwams of our tribe stood here, a great lake rippled wide and long across the land. In its waters a giant beaver sported, and ravaged all the countryside. Mighty Hobomuck, wroth, vowed that the wicked one should die. With an oak cudgel he struck across the beaver's neck – just there, O Netop, in the hollow between head and shoulders. The fearful creature sank gasping to the bed of the lake and his carcass turned to stone."

The Giant Beaver (Pressey, 1910)

"The great beaver preyed upon the fish of the Long River. And when other food became scarce, he took to eating men out of the river villages. Hobomuck, a benevolent spirit giant, at last was invoked to relieve the distressed people. Hobomock came and chased the great beaver far into the immense lake that then covered the meadows, flinging as ran great handfuls of dirt and rock at the beaver. Finally he threw a bunch of dirt so great upon the beaver's head that it sank him in the middle of the lake. Hobomock, arriving a few minutes later, dispatched the monster by a blow with his club on the back of the beaver's neck. And there he lies to this day. The upturned head covered with dirt is the sandstone cliff of Wequamps (Mt. Sugar Loaf), and the body is the northward range. The hollow between is where Hobomock's cudgel smote down his neck."