The Hoosac Range is part of both the Berkshires of western Massachusetts and the southern Green Mountains of Vermont; it is part of the greater Appalachian Mountain chain. Notable peaks include Haystack Mountain and Mount Snow in Vermont and Spruce Mountain in Massachusetts, as well as the Berkshires high point, Crum Hill, in the town of Monroe, Massachusetts.
The 4.75 mile Hoosac Tunnel passes through the range.