Detweiler Run N.A.   Dale J. Luthringer
  Apr 06, 2004 16:40 PDT 
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.

detweiler3.jpg (82819 bytes) 

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
ďmeatĒ 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:

The state has a very brief description below, but it doesnít do the site

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 youíll be in the natural area in about ľ 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 wasnít 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 Iíve 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 didnít 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 wasnít 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 didnít 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 Iíve
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. Iíd 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 dayís 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
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)


Re: Detweiler Run N.A.   David Orwig
  Apr 07, 2004 06:59 PDT 
For those of you who want to learn more about part of Detwiler
Run, see: 

Ruffner and Abrams paper "Relating land-use history and climate
to the dendroecology of a a 326-year old Quercus prinus talus slope
forest. Can. J. For. Res. 28: 347-358. 1998.

Sincerely, DAVE ORWIG

Detweiler Run and Bear Meadows N.A. update   Dale J. Luthringer
  Apr 28, 2004 19:26 PDT 
Bob, Lee, Charlie, Dave, Bruce,

I had the day off from the park today, so I decided to take advantage of
the opportunity to get back into Detweiler Run N.A. to take some
pictures for Bruceís new book. I only got a few pictures (slides)
before my camera flash decided to take a swim in Detweiler Run, not
good. It appears to be working alright, which is a good thing because I
donít have the spare cash to buy a new one at the moment.

My first stop though was to try to reach another branch on the new pitch
pine record that I came across when I was here the last time a few weeks
ago. The clear sunny day helped backlight a twig that I couldnít reach
before. After firing a few shots at click-over, Iím going to settle
with 5ft CBH x 90.9ft. I figured there had to be a 90 footer somewhere.
I probably have about 10 pitch pine in the 80ís, so I think it was just
a matter of time.

....Bear Run material...