The Mt. Holyoke Range constitutes
one of the largest remaining unfragmented forests in Massachusetts
(over 8,000 acres, including Mount Tom). A rich mixture of
oak, pine and hemlock, the forest protects the water quality
of streams that feed the Connecticut River nearby. It is also
a landmark used by thousands of migrating birds in the fall,
including several federally-listed species.
Geology has strongly influenced the plant communities found
here. South-facing slopes, with more nutrient-rich, circum-neutral
soils, support an Oak-Hickory forest more
common further south. By contrast, on north-facing slopes, with
more acidic soils, the forest is largely composed of
Hemlock, White Pine, Birch, Beech, and Maple, an association
more typical of New England’s
cold, moist habitat. Certain rocky outcrops (called “the
Balds”) also support an unusual plant community featuring
species typical of the tall-grass prairie far to the west.
The mountain shelters a thriving wildlife population, including
deer, foxes, songbirds, and raptors.
At Skinner State Park we see large-diameter hemlock trees
along the Tramway Trail’s and Halfway House Trail’s
upper reaches. The hemlocks are so large because they are
“old growth,” some well over 200 years in age.
Trees with multiple trunks are conspicuous by their absence.
This is so because trees here were neither killed by forest
fire nor felled by axe. These woods are telling the
story of land kept as a “natural” tourist destination
for over 150 years.
Rocks tell the story of what was going on when they were
formed and sometimes the story of subsequent events. The
basalt rock that shapes the Range’s spine and south-facing
slopes is a dense igneous rock. Its extremely
fine-grained texture tells us that it cooled rapidly at
when this area was part of an enormous rift valley some 200
million years ago. Its reddish cast indicates the presence
of iron. Some of the basalt on the Range has
shallow, smooth grooves, about as wide as a thumb, running
in long parallel lines. This is the signature of a glacier,
grinding along the rock on its journey south during the
last ice age.
Red-tailed hawks can be seen from the Summit
House during migration. more...
The Mt. Holyoke Range’s ridge and its southern slopes are basalt. more...