[5] Although mostly private property, the Taconics contain a half-dozen sizable state forests and parks, as well as many preserves of lesser acreage protected by land trusts.

In the 20th century, it became attached to the theory of an Ordovician mountain-building event involving much of what is now eastern North America named the "Taconic Orogeny".

[17] The range is part of the Taconic Allochthon, a local rock structure which traveled to its current position from about 25 miles to the east through low-angle thrusting.

[18] Rocks of this allochthon are older than the strata lying beneath, and consist of slate, phyllite, and schist, "plus some minor lenses of limestone."

In opposing Emmons' theory, James Hall of Rensselaer Polytechnic Institute initially gained prominent support from famed international scientists of the day, including Louis Agassiz and Charles Lyell.

[24][25][26] This early phase of ideas about the Taconic Mountains is compared with the Great Devonian Controversy that preoccupied British geologists for part of the 19th century.

From Catamount Ski Area north to the Hoosic River Valley, a straight-line distance of about 50 miles, the crest initially shifts slightly west.

[28] At Pittsfield, the crest shifts west once again to hills contained within Pittsfield State Forest and the contiguous Balance Rock Park and Bates Memorial State Park, where heights include Holy Mount 1,968 feet (600 m), (once the location of religious rituals practiced by a former Shaker community) and Berry Hill 2,200 feet (670 m), notable for its extensive stands of wild azalea.

Significant public property within the Taconics' central segment includes New York's Beebe Hill and Harvey Mt.

Mount Anthony 2,320 feet (710 m), notable for its caves and as the location of the former Southern Vermont College, stands as a satellite peak above the surrounding eroded terrain.

Also part of the Taconic Mountains are the foothills of the Lake Bomoseen region west of Birdseye and Grandpa's Knob, notable for their extensive slate quarrying operations.