This IBA contains the spine of the Green Mountains from Breadloaf north through the Smuggler's Notch area and the entire Worcester Range, a sub-range of the Green Mountains. This is roughly bounded by State Route 125 and the town of Hancock on the south and State Route 15 in Cambridge and Jeffersonville on the north end. State Route 100 is the approximate eastern boundary. The western boundary is in the western foothills of the Green Mountains and is loosely associated with Route 15 in Jericho, and Route 116 from Hinesburg south to Middlebury. The IBA contains a variety of forested habitats, from lowland hardwood forests up to high-elevation spruce fir. Some of Vermont's iconic peaks lie within the IBA as well, such as Camel's Hump and Mount Mansfield (1338 m, the state's highest point). It contains several of the state's well known ski areas and the Waterbury Reservoir. It also contains several sites of the Peregrine Falcon Eyre IBA Complex.
This area contains a wide variety of forested habitats, including high-elevation spruce-fir forest, mixed hardwood-conifer forest, and northern hardwoods forest. This is some of the largest area of spruce-fir, a critical habitat type for Bicknell's Thrush and Blackpoll Warbler, in the State of Vermont. Lower elevations also support many other forest species, including Black-throated Blue Warblers and other species targeted as part of the Vermont Forest Bird Initiative.
Several threats are present to this IBA. Some of the most important for mountain-breeding species such as Bicknell's Thrush are acid rain and atmospheric mercury deposition, which alter forested communities and introduce toxins. Climate change has the potential to reduce and even eliminate high-elevation spruce-fir communities in Vermont. Possible future construction of communications towers and wind turbines would fragment habitat and present hazards to migrating birds. Expansion of existing ski areas could also fragment habitat.
Most of this IBA is located on state land (Mount Mansfield and C.C. Putnam State Forests and Camel's Hump State Park) and federal land (Green Mountain National Forest), with much of the remainder in private ownership.
In addition to large areas of northern hardwood and mixed forest, the IBA contains relatively large areas of high-elevation spruce-fir forest, a rare community in Vermont.
The IBA contains miles of popular hiking trails on some of Vermont's iconic peaks, as well as ski areas and a mountain/forest research area on Camel's Hump. The Vermont Center for Ecostudies (VCE) conducts its Mountain Birdwatch (MBW) program in the IBA, in addition to the rest of the mountains of the northeast.