Bob,
Bruce, et. al.,
Last Wednesday I was took the opportunity to visit the 463 acre
Detweiler Run Natural Area located in the Rothrock State Forest
in
Huntingdon County (central PA). I believe that all of that
acreage is
definitely old growth forest. This site is located in a valley
system
that stretches in a general NE to SW direction with Thickhead
Mountain
on the east side and Detweiler Run Road on the west side.
Detweiler Run
flows about 2 miles in a SW direction into Stone Creek and the
noteworthy Alan Seeger Natural Area.
Detweiler
Run Other
Ostuno Galleries
The Detweiler Run valley experiences close to 500ft of relief
from the
stream bed to the top of Thickhead Mountain. Thickhead Mountain
is in
the range of 2500-3000ft in elevation. The southeastern portion
of this
site has experienced fire history within the last 150 years as
evidenced
by old pitch pine and chestnut oaks that dominate this section
of the
stand. The stream bed is dominated by old growth E. hemlock and
great
rhododendron. The E. hemlock and rhododendron continues almost
all the
way to the top of the mountain on the east side. The E. hemlock
and
rhodes continue only a short distance up from the stream on its
western
side, then changes into what appears to be secondary old growth
up to
Detweiler Run Rd.
The entire site is full of small sharp medicine ball sized
boulders.
Walking is difficult, even on the established Mid-State Trail
which
travels on the western side of the stream. The trail does not go
directly through the best of the old growth, it skirts the
primary old
growth on its western side, but is close enough to entice one
into the
“meat” of this exceptional area.
I was very impressed with the ancient E. hemlock in this site.
Heights
of most species were unimpressive with hemlock nearing 124ft and
white
pine nearing 135ft. I suspect hemlock in this area to surpass
500 years
old. Nearby Alan Seeger N.A. has hemlock that will go to the 600
year
age class. The hemlocks at Detweiler show the same impressive
features.
Please visit the following link for directions and maps to this
site:
http://www.purplelizard.com/images/html/skiing/detweiler.htm
http://www.purplelizard.com/images/html/driving/322%20Seeger.htm
The state has a very brief description below, but it doesn’t
do the site
justice:
http://www.dcnr.state.pa.us/forestry11404/stateforests/forests/rothrock/
rothwild.htm
The Detweiler Run Natural Area and Detweiler Run Rd are not
marked on
the Bear Meadows Rd which takes you past this site. Detweiler
Run Rd is
closed to vehicles. The best place to park, is at the unmarked
trailhead for the Mid-State Trail which is located at the
Detweiler
Run/Bear Meadows Rd hair pin curve junction. Take the Mid-State
Trail
downhill, and you’ll be in the natural area in about ¼ mile.
I crossed the stream where Bruce suggested (superb directions by
the
way), at the extreme SW end of the natural area, then proceeded
upstream
and uphill in a zigzag manner searching for some ancient tree
specimens.
It wasn’t long before I came upon some nice pitch pine. I
thought they
may go to the 80ft range, and possibly higher, so I thought I
might just
have to measure them. Turns out, I broke the previous PA pitch
pine
height record of 87.7ft two times. The first pitch pine I
measured went
to 88.2ft, the 2nd tree went to 88.9ft. The 88.9ft tree also
turns out
to be the fattest I’ve found so far too at 5ft CBH.
As I continued upstream on the eastern side of Detweiler Run,
the forest
changed from being dominated by old chestnut oaks, N. red oaks,
black
gum, and tuliptrees (fire history area); to being dominated by
ancient
E. hemlock and great rhododendron. Although the trees were
shorter in
stature, it reminded me of the ancient stands of hemlocks in the
Smokies, Alan Seeger, and Cook Forest. I came across one jaw
dropper
single stem hemlock at 13.4ft CBH x 112.6ft high (40 43.130N x
77
44.586W). This tree in particular is one that I think may break
the 500
year age class, possibly older. It was growing on a small
boulder, was
partially hollow, had large and small gnarled twisted branches
and knobs
along its trunk with a thick twisted root mass. This is probably
the
fattest hemlock in the stand, although I did come across a
couple of
nice ones in the 11ft CBH range.
From this point, I continued uphill in a vain attempt to see how
far the
old growth went up the eastern slope. The Rhodes became
incredibly
thick at this point, many times the only way through was to
crawl on my
hands and knees to take the easiest path. I didn’t quite have
to low
crawl, but it was pretty darn close. It really was like a
virtual wall
of rhododendron about 15-20ft high. The higher I got, the
smaller the
hemlock and the thicker the Rhodes became. I got close to the
ridge top
where the contours were starting to round off a bit, but decided
to turn
back in a NW direction to try to work my way back down towards
the
stream. It appeared that the old growth continued right to the
top of
the mountain.
It wasn’t much easier on my new track through the rhodo forest
downhill
in a NW direction. I just about had to roll on top of the Rhodes
to get
through, luckily I didn’t run into any tics that wanted to
hang on for a
free lunch. I made it to the stream, crossed it, and continued
upstream
on its western side. Found a couple more nice hemlocks and some
ancient
black gum. One in particular was the largest forest grown
specimen I’ve
found to date at 8.7ft CBH x 88.2ft high.
I continued a short distance west, picked the Mid-State Trail
back up
and continued northwest skirting the western edge of the primary
old
growth until I came to what I perceived to be close to the old
growth
boundaries. I then turned back and took the Axehandle Trail west
and
uphill to Detweiler Run Rd. Found a couple more ancient black
gum and
N. red oak. One red oak that fell across the path yielded 245
rings at
6.7ft CBH 15ft up from its base. Another smaller N. red oak
yielded 122
rings at 3.7ft CBH also roughly 15ft up from its base. I was
serenaded
by a barred owl as I proceeded the last mile SW down Detweiler
Run Rd
back to my vehicle.
I generally agreed with old growth acreage estimate put out by
the
state, although there probably is a bit more acreage that could
be
included near the top of Thickhead Mountain. I’d suggest just
over 500
acres of old growth. My initial assessment put the acreage at
roughly
504 acres, but it definitely needs some tweaking.
This is definitely an impressive site. The best stuff though is
definitely off trail, but very difficult walking not conducive
to
organized interpretive hikes. If anyone plans on going to see
the well
marked old growth at Alan Seeger, I would suggest a short trip
to
Detweiler Run as well.
I noted the following old growth species:
Species Est.
Age
Black birch 175
Black gum 200+
Chestnut oak 200
E. hemlock 500+
E. white pine 200+
Pitch pine 150+
N. red oak 250
Tuliptree 200
Yellow birch 175
The day’s stats follows:
Species CBH Height Comments
Black birch 6.9 69.1+
Black birch 6 81.1+
Black gum 6 60.4
Black gum 8.7 88.2 personal
largest forest grown
specimen
Black gum 6.9 96.1+
Black gum 7.4 97.9
Black gum 7.8 100.9
Black oak 5.3 96.1+
Chestnut oak 6 81.1
Chestnut oak 7 84.1+
E. hemlock 7.3 96
E. hemlock 9.4 97.3
E. hemlock N/A 101.5
E. hemlock 11.2 109.2
E. hemlock 13.4 112.6 ancient
tree 500+?
E. hemlock N/A 113.9
E. hemlock 10.1 114.5
E. hemlock 8.5 116.7
E. hemlock 11.7 117.8
E. hemlock 8.5 119.1
E. hemlock 11.5 123.7
E. white pine 9 110.8
E. white pine 9.5 115.1
E. white pine 9.5 117.7
E. white pine N/A 118.3
E. white pine 8.7 120.5
E. white pine 9.6 124.5
E. white pine 9.7 134.6
N. red oak 6.9 96.1
Pitch pine 4.8 86.4
Pitch pine 4.5 88.2
Pitch pine 5 88.9 new
PA height record (40
42.999N x 77 44.804W)
Red maple 4.4 90.1+
Red maple 6.9 101.6+
Tuliptree 10.5 103.8
Tuliptree N/A 105.4
Tuliptree N/A 108.9
Tuliptree N/A 111.1
Tuliptree N/A 116.4
White oak 4.9 90.1+
White oak 4.8 102.1+
Yellow birch 6 69.1+
Detweiler Run Rucker Index follows:
Species CBH Height Status RI
E. white pine 9.7 134.6 104.45
E. hemlock 11.5 123.7
Tuliptree N/A 116.4
White oak 4.8 102.1+
Red maple 6.9 101.6+
Black gum 7.8 100.9
N. red oak 6.9 96.1+
Black oak 5.3 96.1+
Pitch pine 5 88.9 tallest
PA
Chestnut oak 7 84.1+
Nearby Natural Area Rucker Indices
Site Rucker
Index
Alan Seeger 111.13
Joyce Kilmer below
90
Bear Run below
90
Snyder-Middleswarth not
enough species (only 3: EH 145.3, WP 127.6,
YB 90.9)
Dale
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