20 TACONIC PHYSIOGRAPHY. 
(5) That of the Castleton River in Castleton and West Rutland. 
The last three have east-west courses and reach the 800-foot level, j 
The Taconic Range is so deeply and widely cut by the Hoosic and 
Walloomsac valleys that the upland has been brought below the 1,500- 
foot and 2,000-foot zone, and only Mount Anthony rises above them. 
There are also minor transverse valleys, like that in Canaan, N. Yl, 
used by the railroad, and that of the Kinderhook in Hancock and 
Stephentown, neither of which has reached the 800-foot level, and an 
incipient one in Poultney and Middletown, of which only the western 
part is at 800 feet. 
Longitudinal valleys. — North of the Taconic Range, in Addisoaij 
County, a gentle rise to an elevation of 500 feet separates the valley 
of Lake Champlain from the Vermont Valley. The Vermont Valley, , 
which north of Dorset Mountain separates the two ranges, is divided 
into two longitudinal valleys by a series of hills rising above 1,500 
feet and even reaching 2,000 feet (Danby Hill, Clark Mountain)! 
This series is continued farther north in Boardman Hill (1,313 feet j 
and Pine Hill (1,445 feet). The map shows only a portion of the 
eastern valley. Its narrowest part is east of Dorset Mountain, wheri t 
the Green Mountain Range rises very steeply to the 3,000-foot leve 
At West Rutland the Taconic Range itself is subdivided lengthwisd 
and a third valley intervenes, which, however, dies out in Pittsford 
South of Dorset Mountain the Vermont Valley is regular until withij 
a few miles of the Massachusetts line, where it may be said to b 
shut off by a mass which joins the base of Mount Anthony to the 
Green Mountain Range. The lowest point in the crest of this mas; 
is at Pownal Center, at the 980-foot level. 
In northwestern Massachusetts the Vermont Valley may be sal 
either to have receded 6 miles eastward, following the embayment in 
the Green Mountain Range, or else, following the Taconic Rang 
proper, to end near South Williamstown or in the Hancock Valley 
There are structural reasons for the latter view. 
^Yest of the Green Mountain embayment there are four longitudinal 
valleys — the valley along the foot of Hoosac Mountain, that whic 
separates the Grey lock mass from the Taconic spur, the Hancoc 
Valley between the spur and the main range, and that between the 
Taconic Range and the Rensselaer Plateau. South of the Pittsfield 
Plain the topography is again complex; there are three longitudinal 
valleys, which near the Connecticut line become merged in the 
Housatonic Valley. 
Rensselaer Plateau.— Between latitude 42° 30' and 42° 50' and 
west of the Taconic Range is a very irregularly bounded upland, 
about 80 square miles in area, above the 1,500- foot level, with a 
small eminence on its eastern side rising above 2,000 feet. It is sepa- 
rated from the Taconic Range by the Little Hoosic and Kinderhook 
