6 BULLETIN 140, U. S. DEPARTMENT OF AGRICULTURE. 
Pittsfield to Stockbridge the main valley is 1 to 2 miles wide, but it 
then is closed in by mountains. Near Great Barrington and the 
Egremonts it is again 5 miles wide. Narrowing at Sheffield to 3 
miles it again broadens to 6 miles at the State line, narrowing again 
a few miles to the south. Across the western end of Connecticut it is 
broken into a number of small isolated areas. 
THE TACONIC MOUNTAIN GROUP. 
West of the Hoosac Valley lies a thick local mountainous group 
with general elevation above 2,000 feet, known as the Taconic Moun- 
tains. These mountains are parallel to the Housatonic Valley 
and form its western boundary. They lie partly in Massachusetts 
and partly in the State of New York. Their steep slopes afford little 
good farming land. Their highest point in Massachusetts is ap- 
proximately 2,800 feet. Geologically these mountains and the lower 
region west to the Catskills correspond to the broad band of shales, 
which give rise to the Berks soils of Pennsylvania, where they adjoin 
on the north the Lehigh, Lebanon, and Cumberland Valleys. 
The highest mountain in southern New England, Mount Greylock, 
with elevation of 3,505 feet, lies between the two branches of the 
Berkshire Valley, southeast of Williamstown, Mass. 
The general surface of the Western and Eastern Highlands and of 
the Southeastern Plateau is very irregular, yet the upland skyline is 
approximately even. The surface of this sloping region passes be- 
neath the sea along the existing shore line with no sudden descent. 
The coast line merely marks the points of zero elevation along this 
tilted surface. The rise is gradual to a maximum of 2,000 feet in the 
northwest corner of Massachusetts. 
THE SOIL MATERIAL. 
The soil material found in southern New England is called glacial 
material by geologists, meaning that it was placed where it now lies 
by deposition from a former ice sheet. It was removed a short dis- 
tance, however, and to all intents and purposes it is the product of 
the weathering, breaking up, and more or less grinding up of the 
rocks which occur in the region and constitute its foundation. 
These consist, with the exception of the rocks in the Connecticut 
Valley, of ancient crystalline rocks, such as gneisses, schists, slates, 
and various igneous rocks. They are, so far as the soil material 
is concerned and considered in a broad way, essentially uniform 
over the whole State. In the Connecticut Valley the rocks consist 
of soft sandstones and shales with a few bands of hard igneous 
rocks which form the ridges already referred to. 
The Cape Cod region differs from the rest of the region in that 
the existing land and its elevation is not due to a solid rock founda- 
