Tsuga Search progress report

October 2006


Submitted by Will F. Blozan and Jess D. Riddle

Eastern Native Tree Society

Photos by Will Blozan; graphs by Jess Riddle




The past six months have found us immersed in hemlock woolly adelgid treatments, proposals, and consultations. The Tsuga Search has continued in various degrees of focus. With the full canopy of new leaves obscuring new finds, we focused more on climbing known trees and completing the tree and shrub plots on previously discovered large and tall trees.


Tree climbs

Eight trees have been climbed and measured since the last Tsuga Search report of February, 2006.


Date                           Tree                                        Location

March 5th                    “Caldwell Colossus”              Caldwell Fork, NC, GRSM

March 31st                  “Cheoah Hemlock”                Ammons Branch, NC, USFS

April 27th                    “Winding Stairs Loner”         Winding Stairs Br., NC, GRSM

May 17th                     “Woolly Mammoth”                Kalanu Prong, TN, GRSM

May 18th                     “Tom’s Tower”                       Lowes Creek, TN, GRSM

July 16th                      “Jim Branch Giant”                Jim Branch, NC, GRSM

September 9th           “Yonaguska Hemlock”          Winding Stairs Br., NC, GRSM

September 14th         “Rough Fork Hemlock”         Rough Fork, NC, GRSM


Climb data

Tree                                        CBH               Girth 100’      Height            Volume ft3

Caldwell Colossus               16’10”             8’4.5”              159.7’             1385 ft3

Cheoah Hemlock                 16’0”               9’3”*                158.0’             1564 ft3

Winding Stairs Loner           15’6”               7’4.5”              158.8’             1180 ft3

Woolly Mammoth                 15’1”               8’6”                 153.2’             1262 ft3

Tom’s Tower                          14’4”               7’10”               163.7’               971 ft3

Jim Branch Giant                 13’1”               9’2”                 166.7’             1188 ft3

Yonaguska Hemlock           14’7”               9’6”*                168.9’             1367 ft3

Rough Fork Hemlock          14.1”               8’11”               157.7’             1202 ft3          

*Interpolated from combined cross sectional area of multiple trunks


Vegetation plots

All of the above trees have had tree and shrub plots completed around them. The shorter heights of the adjacent trees confirmed that the target trees are often in open, emergent canopy positions, even when on a steep slope. The target trees often tower above the surrounding canopy by 20 feet and at times up to 60 feet. The tallest trees adjacent to a targeted hemlock occurred around the Tsali Hemlock, the tallest eastern hemlock ever recorded at 169’10”. Vegetation plots were also completed around the Tsali Hemlock which remains the height record holder for the species. Although this tree likely died from drought in 1999, it remains fairly intact, and we plan to pull an increment core to attempt to age it.


In the eleven plots with canopy tree plots completed, a total of 19 species were recorded with only eastern hemlock represented in all plots. Mountain silverbell was in all plots but one- where it grew just beyond the plot edge. Birch was recorded in all plots, but neither black nor yellow were found in all plots. Basal area of the trees over 4 inches (10 cm) dbh ranged from 82 ft2 to 266 ft2 per surface acre, not including the target tree. Shrubs covered 7 to 56 ft2 per acre, heavily dominated by rhododendron. Only one plot, that of the Yonaguska Hemlock, contained another hemlock over 1000 ft3 in trunk volume.


The almighty rhododendron…

Nineteen species were recorded in the shrub subplots. Shrub basal area ranged from 7 ft2 to 56 ft2 per acre. Rosebay rhododendron occurred in nearly all the shrub plots. The only site to lack a significant rhododendron component was the Long Branch Hemlock (although it did occur sporadically within the plot). In fact, of the 113 shrub sub-sample plots occurring on land, 92 (81%) contained at least one stem of rhododendron (seven were in a stream or on rock). In summary, the shrub plots revealed that rhododendron was ubiquitous (duh…). A total of 1211 shrub stems have been measured thus far; 841 of them (70%) are Rhododendron maximum (not including the 35 that were recorded as trees!). Rhododendron ranged from 0 to 100% of the stems and 0 ft2 to 54 ft2 in basal area per acre. Interestingly, of the eleven rhododendron trees we have cored, 5 were over 100 years old, the oldest reaching 134. A park height record of 30.7 feet was found in the shade of the Winding Stairs Loner.


Tree cores

Trees cored ranged in age at BH from a 27 year old yellow birch to a 371 year old eastern hemlock (which was an understory tree of only 13 inches diameter). Black birch was the next oldest species at 323+ years with a 292 year old tuliptree- the only other species to exceed 200 years so far. The black birch may be a new eastern age record for the species when confirmed by fellow ENTS member and dendrochronologist Dr. Neil Pederson at Eastern Kentucky University.


All plots had a solid tree at least 192 years old at BH. Core features and age data indicate fairly large disturbances surrounding the Cheoah and the Caldwell Colossus. These events likely cleared the surrounding trees and supplied the target tree with the boost of sunlight and canopy dominance that resulted in the huge trunk volume.


Introducing the frame mapping technique

The Cheoah and Yonaguska hemlocks have provided us with new insight into the morphology of eastern hemlock. These trees, with fused trunk sections, provided us with the opportunity to apply the “frame mapping” technique described below to obtain cross-sectional area of distorted trunk sections.


The Cheoah Hemlock, which grows outside of the Smokies on USFS land near Highlands, NC, turned out to have set the bar even higher with regard to how big eastern hemlock can get. This complex tree had a huge crown with multiple leaders and subordinate reiterations. The main trunks were easy to measure but the fused sections where they fork posed a challenge. Wood volume is calculated by measuring the girth at the “ends” of round trunk sections. The measured sections are selected based on changes in the trunk shape or profile and the resulting “pieces” added together to calculate the volume of the entire tree. The fused sections, however, are anything but round and a direct girth measurement over-estimates the area and subsequently the volume of the section.


Lacking high-tech gadgetry like our western Tsuga Search advisor, Dr. Robert Van Pelt, we resorted to a low-tech but surprisingly functional system using two, six foot stakes. In this case we used very stiff bean poles from a garden store. The set-up goes like this:


With two climbers, each on opposite sides of the tree, an area of fusion is selected to be measured. A rectangular frame is erected around the section of truck to be measured.  The poles make up opposite sides of the frame, and lengths of thin rope pass through holes at either end of the poles to form the other two sides. Shortening the ropes draws the poles tight against the trunk and clamps the frame in place. The frame then serves as the basis for an imaginary Cartesian coordinate system perpendicular to the long axis of the trunk. One pole is chosen to represent the x-axis, and the origin is chosen such that the y-axis is tangent to the trunk. Once the origin is fixed, we move along the pole and with a stiff carpenters tape measure the perpendicular distance from the pole to the edge of the trunk; thus each point we measure to the trunk is assigned an x-value, the distance along the pole from the chosen origin, and a y-value, the distance from the pole to the trunk. Using those coordinates, we can plot the outline of the trunk and calculate the area using formulas in an Excel™ spreadsheet. We measured at changes in the trunk profile and to the nearest 1/8th inch. Graphing of the data illustrates the cross-sectional profile of the fused trunk. See example below.



Using this technique we also re-climbed the Yonaguska Hemlock on Winding Stairs Branch to complete a frame mapping of the fused codominant leaders. This resulted in the most accurate volume of this dead giant. To our surprise, the shortcuts taken during the first climb in 1999 significantly overestimated the volume. It no longer reigns as the largest confirmed eastern hemlock in the Smokies. This title now goes to the Caldwell Colossus.


New insights into hemlock morphology

It is very clear that a large hemlock has to be a canopy dominant and quite tall. It likely must also have had a long period of time in an exposed, low competition or high light canopy environment. The foliar area clearly is linked with the mass of the tree; a big crown can capture lots of energy to make lots of wood. Multiple trunks (bifurcations) and large reiterations may play an important role in the ultimate size of the tree. The largest known tree, the Cheoah Hemlock, has multiple tops and is far larger than a comparably sized single-trunked bole such as the Caldwell Colossus. The Yonaguska Hemlock with its relatively modest diameter has two leaders at 100’ up, but the combined cross-sectional area is equal to a single stem 9’6” in girth. A girth this size has never been documented in a single-trunked tree (although see “Close calls” below…). Essentially, bifurcation of the tops may allow more branches to be produced with minimal investment in more wood.


Hence, it may be no surprise that the Cheoah Hemlock is the largest known hemlock. Basically, the growth and environmental conditions are ideal; a very tall, dominant tree with an immense crown, bifurcated tops, and multiple reiterations in a high rainfall climate = massive tree.


Likewise, the Jim Branch Giant with its slim 13’1” girth but extreme height was larger than either of us thought. It simply tapered so slowly that its modest trunk was still able to rack up lots of cubes. In fact, of all the climbed trees having a single trunk at 100’ its 9’2” girth at this height is the largest we’ve documented. Furthermore, its multiple trunks above 110’ certainly allowed it to broaden its crown and provide the photosynthetic area needed to amass the wood so high in the tree.


Search areas

New searches have been completed on Surry Fork, Buck Fork, Chapman Prong, Eagle Rocks Prong, and in the vicinity of the Gabes Mountain and Maddron Bald trails. The immense trees found in 1998 on Buck Fork proved to be elusive and were not relocated on a scouting trip in late July. This trip did yield a new potential Tennessee State Champion white ash which is also the tallest known white ash in Tennessee at 148’. A huge hemlock on Chapman Prong will be revisited with the monocular in spring 2007. Other than that tree no new hemlocks have been discovered that merit further measurements or climbs.


Close calls…

A large hemlock on the Gabes Mountain Trail was visited and measured with the monocular. Its impressive 16’1” girth was not maintained far up the trunk so the tree only scaled ~973 ft3. A vigorous tree growing on an unnamed tributary between Indian Camp Creek and Jones Branch nearly made it into the “160 Club” with a total height of 156.8’. This young tree had a spire top and with treatment may continue upward. This tree is the tallest hemlock known from the Greenbrier District. Two large hemlocks were revisited on the Middle Prong of the Little Pigeon River and determined to be too small for the project.


Most significantly, however, we just missed a giant tree on Little Bald Branch in Cataloochee. It had fallen, and by “reconstructing” the broken pieces and measuring the remaining snag it appears that this tree could have been a new Smokies record. The girth was impressive at 15’10” but what was so shocking was that the portion of the trunk at ~100 feet up was 10’1” in girth. Assuming a typical taper and extending the CBH to the ground this portion alone would amass nearly 1300 cubic feet of wood. Above 100 feet the tree split into multiple tops and it had a massive reiteration below 100 feet that would add more to the total volume. Total volume could easily have been over 1400 ft3!


Monocular update

The climb of the Winding Stairs Loner, Tom’s Tower, Jim Branch Giant, Woolly Mammoth and the Rough Fork Hemlock afforded us the opportunity to better assess the accuracy of the monocular. Presented below are the monocular data and the climb data with the percent error indicated. We are still within the 5% error goal we set out to achieve, assuming the climb data to be the most accurate. We believe much of the error is due to the limitations of the rangefinder, including difficulties of determining precise distances to the target and the few measurement points conducive to a reflective bounce. One of the rangefinders was discovered to read a yard long which would increase the value obtained and over-estimate the volume (and height). The Woolly Mammoth was measured from a much greater distance than the other three trees which would reduce the influence of the extra yard. Tom’s Tower, the Rough Fork Hemlock, and the Jim Branch Giant were measured from only one side, but the results are nonetheless satisfactory. The Woolly Mammoth and the Winding Stairs Loner were both measured from two or more sides. Note: the Jim Branch Giant was measured with a “target quality” scale within the rangefinder (not specifically designed for diameter estimations) and although the numbers below indicate no error, the girths obtained do not match those of the actual climb; we were just lucky!


Tree                                        Monocular volume             Climb volume          Diff

Winding Stairs Loner            1228 ft3                                   1180 ft3                       +3.5%

Tom’s Tower                          993 ft3                                     971 ft3                         +2.3%

Woolly Mammoth                  1270 ft3                                   1262 ft3                       +0.6%

Jim Branch Giant                  1188 ft3                                   1188 ft3                       0.0%

Rough Fork Hemlock            1220 ft3                                   1202 ft3                              +1.5%


In response to these errors, we have purchased a new rangefinder, a Nikon ProStaff 440 which has so far proven exceptionally accurate. One change in protocol we may establish in our monocular field methods is using a single baseline measurement to the base of the tree and a single laser shot distance to the highest portion of the trunk that is clearly visible. We have been measuring distance to every portion of the trunk measured which takes more time and likely does not result in significant gains in accuracy. By using only the two distances we can minimize errors in the sections in-between and simply interpolate the distance based on the angle obtained from the clinometer. An added advantage is being able to measure a portion of the trunk visible to the monocular but not directly measurable by the laser, as happens when fine branches obscure a shot to the trunk. Of course, this will only work with trees that are straight and not forked. See diagram below.


With this idea in mind we mathematically applied this change in protocol to two trees we have already measured, one that has not been climbed and another that has been climbed. The tree that has not been climbed had a suspiciously high volume based on the monocular data. We suspect (and have since confirmed) that the laser was erratic and reading long. By applying the procedure above, a much more realistic volume estimate was obtained since it was based on two relatively solid measurements that do not compound errors.


We also re-ran the calculations on the Woolly Mammoth using the new protocol. The initial measurements were done by measuring the distance to each measurement point. In the study of the new protocol we simply used the basal and top measurements and interpolated the others as in the diagram above. The adjusted monocular estimate was but three cubic feet less than the climb data.


Volume modeling examination

A great deal of time and effort is needed to traverse the field conditions often encountered in the hemlock forest of the Smokies. Thus, we have been very interested in minimizing monocular and tree climb efforts while still gathering accurate results. Fortunately, we are in possession of a data set that will allow examination of the number of measurements needed to obtain satisfactory results and minimize time staring through the monocular or hanging aloft. The Sequoyah Hemlock, climbed in 1998, was measured in increments of 3 feet from the top to the base. The resulting 47 data points can now allow us to randomly or non-randomly select measured points on the tree and calculate the volume based on only these selected points. By comparing results we can determine if additional measurements are more accurate or if just a few will suffice. Again, we are assuming that the climb data is the most accurate representation of the actual volume of the tree.


We devised multiple scenarios based on random or set measurement intervals of nine feet. For all scenarios we kept the basal measurements consistent as we would in the field. Results ranged from a minimum of 1162 cubic feet and a maximum of 1219 cubic feet by random selection of grouped intervals. The trials fell within our goal of 5% or less overall difference from the climb and suggests the more measurements the better.


Measurement intervals                 calculated                 Climb             Difference

Random 1 of 3 min.                          1177 ft3                       1188 ft3                       -0.9%

Random 1 of 3 max.             1201 ft3                       1188 ft3                       +1.1%

Random 1 of 5 min.                          1162 ft3                       1188 ft3                       -2.2%

Random 1 of 5 max.             1219 ft3                       1188 ft3                       +2.6%


Since nine feet is close to what is often measured in the field, we ran some tests by keeping the nine foot interval but starting it at three or six feet from the top. These data turned out to be surprisingly different but still within 2.3% of the climb results.


Measurement intervals                 calculated                 Climb             Difference

9 feet constant top                            1180 ft3                       1188 ft3                       -0.7%

9 feet constant 3’ from top               1215 ft3                       1188 ft3                       +2.3%

9 feet constant 6’ from top               1170 ft3                       1188 ft3                       -1.5%


The trunk profile was rather scalloped when graphed at three foot intervals (see chart below). One scenario tended to select the inner points (narrowest) and the other selected the outer, or wider points. Basically, the volume differences were determined by which change in profile was selected. The advantage of climbing a tree is being able to literally sight down the trunk and pick up profile changes to measure.



Fall/Winter plans

We plan to visit, climb and complete plots on previously located or climbed trees. These include plots for the Gabes Mountain Hemlock, the Sequoyah Hemlock, the Dunn Creek Hemlock, and the unnamed tall tree off Porters Creek. Little Bald and Big Bald Branch off Caldwell Fork will be more extensively searched this fall after leaf drop. This area may prove to be the epicenter of tall hemlocks. At that time the Caldwell Colossus will be checked for recovery growth and retreated.


We also plan to devise a basal or footprint mapping technique based loosely on the frame mapping in the canopy. Dr. Van Pelt feels we may be under or over estimating the amount of wood in the base of the tree. We are well aware of this but are challenged by the field practicality of the technique and great expense in time with minimal gains in accuracy. We will investigate some ideas we have in mind and present them in the next update if they prove successful.



Lichen garden in the Rough Fork Hemlock

September 2006
Current ranking of the ten largest climbed eastern hemlocks

October 2006


Tree                                                    CBH               Height            Volume ft3

Cheoah Hemlock                             16’0”               158.0’             1564 ft3

Caldwell Colossus                           16’10”             159.7’             1385 ft3

Yonaguska hemlock                        14’7”               168.9’             1367 ft3

Long Branch hemlock                     16’0”               143.6’             1294 ft3

Woolly Mammoth                             15’1”               153.2’             1262 ft3

Rough Fork Hemlock                      14’1”               157.7’             1202 ft3

Sequoyah Hemlock                         15’8”               144.0’             1188 ft3

Gabes Mountain Hemlock              16’3”               121’                1188 ft3

Jim Branch Giant                             13’1”               166.7’             1188 ft3

Winding Stairs Loner                       15’6”               158.8’             1180 ft3


Median tree dimensions               15’8”              158’                1262 ft3



View from the Woolly Mammoth overlooking Kalanu Prong, TN

May 2006

Graphed tree profiles based on tree climb data

October 2006




Profile graphs and forked tree composites by Jess Riddle
Forked tree profile and stem map: Cheoah Hemlock


Forked tree profile and stem map: Yonaguska Hemlock


Forked tree profile and stem map: Jim Branch Giant  


Tree profiles: all trees[1] >1180 ft3

October 2006


Tree profiles: climbed trees > 163’ and measured for volume

October 2006


Eastern hemlock tree climbs as of October 2006



A reiterated limb on “Tom’s Tower”, May 2006

Climb of the Woolly Mammoth May 17th, 2006


This huge tree grows on the western face of Woolly Tops Mountain, a rugged, spruce covered peak topping out at 5463 feet. Since this tree is vastly larger than any other in the area we dubbed its pet name, the “Woolly Mammoth”.


Just about 25 feet north of the stream, the Mammoth has enjoyed little crown competition on the south side which has resulted in a huge mass of limbs and a slight but pronounced lean towards the creek. In one section, two huge limbs jutted out of the trunk just inches from each other in the same direction (tusks, perhaps?). One of these turned up and splayed out into a complex of small reiterations.



Views from the stout top were incredible; high vistas of cloud-laden spruce, fresh greens of new sugar maple and basswood leaves, and the newly opened display of yellow buckeye blooms and moss covered boulders as viewed from above.





The hemlocks however, were not in fresh green spring plumage as the hemlock woolly adelgid has a firm grip on the area. The mammoth was covered head to toe with adelgid and portions of the crown had begun to decline. Surprisingly though, the top was still growing in places and flower buds were about to break.

Climb of the Caldwell Colossus March 5th, 2006

In the dim light of the last day of a 2002 survey in upper Caldwell Fork, ENTS tree hunters stumbled upon a massive hemlock over 16’ in girth and lasered the height to 159.9’ tall. Thoroughly impressed, we vowed to return and climb it. We named it the “Caldwell Colossus”, a name that would prove well justified. The arrival of HWA sparked a renewed interest and sense of urgency to document the tree. So, on a cold March day, accompanied by two park staff, we ventured into the realm of the Caldwell Colossus.














While traversing the canopy, I noticed that the Colossus had about one square foot of green growth which was entirely reinfested with HWA.






The surrounding trees were likewise defoliated, gray, or dead. NPS staff treated the Colossus and numerous surrounding trees in the hopes that they will recover.


The volume calculations based on the climb data indicated a wood volume of 1385 ft3. This is the largest non-forked specimen known of the species and currently the largest hemlock thus far documented in the Smokies.

Climb of the Cheoah Hemlock, March 31st, 2006


Having gained more experience with hemlock morphology, Jess and I knew that this tree would re-write the books about eastern hemlock dimensions. The perfect habitat and reiterated crown coupled with massive girth and height led us to conclude we had a new champion even before the climb. As I ascended, with Jason Childs assisting, I was floored by the immense mass of wood I was climbing on and the expanse of the interior of the crown.

The sheer width of the crown was astonishing and trunks and limbs had fused together into a matrix of wood. The single leader that the tape was set on scaled 1231 cubic feet by itself, making it one of the top five hemlocks thus far documented. The multiple tops and reiterations scaled another 333 cubic feet for a grand total of 1564 cubic feet! This is nearly 12% larger than any other hemlock thus far documented, and as such firmly secures the title of the largest eastern hemlock ever accurately documented and furthermore claims the title to the largest evergreen conifer in the eastern United States.


Fortunately, the USFS allowed for the treatment of this tree on June 6th, 2006.

Climb of the Winding Stairs Loner April 27th, 2006

For this climb, we were graciously assisted by Bob Weber, a two-time ISA World Tree Climbing Champion and hemlock preservation enthusiast. Bob has been tireless in his efforts to control HWA in western NC.


The climb revealed the Loner to stand 158.8’ tall and contain 1180 cubic feet of wood. Its impressive girth was not maintained to the degree to achieve the status of a truly huge tree, but given successful HWA treatments it should continue to get more massive.



This tree is also one of the most accessible of the big, tall hemlocks. It is literally just a few minutes steep walk off the unpaved entrance road into Cataloochee, and grows in one of the few remaining green groves of hemlock remaining in Cataloochee Valley. For this reason we have recommended aggressive soil treatments to try to preserve large sections. This same creek once contained the tallest and the second largest eastern hemlocks in the Smokies, and at one time grew four hemlocks over 160’.


Upper and lower Winding Stairs Branch may contain some of the finest hemlock forests remaining in salvageable condition in the NC portion of GRSM. Fortunately, a portion of this grove has begun to be treated that includes the Winding Stairs Loner.

Climb of Tom’s Tower May 18th, 2006


The search for this tree was a direct result of a record in Will’s notes from 1997. We jokingly named the tree for Tom Remaley, the NPS hemlock woolly adelgid supervisor, but it has since stuck. It seems fitting, as Tom is the “champion” of the Smoky Mountain hemlocks and leaving a vast legacy of preserved forests for the future.

It rained as soon as we arrived for the climb but we waited and the day turned out gorgeous. The base is just 11’ from the waters edge and the tumbling, rocky torrent of Lowes Creek made communication difficult due to the noise. Once I was in the tree, I was rewarded with grand vistas of almost uninterrupted old-growth forests.





Tom’s Tower is no longer growing but has retained much of its crown and should respond well to treatments before its second flush of a new crown. Every limb up to 3 inches in diameter- including bark- was entirely covered in new woolly adelgid (second brood of the spring).


Virginia creeper was found to have grown to 130.5 feet up the trunk.

The Tsali Hemlock revisit June 8th, 2006


Since the Tsali Hemlock was the tallest eastern hemlock ever accurately documented, we felt it was more than justified to include this tree in the Tsuga Search. It was also climbed in 1998 by Will and Brian Hinshaw for volume, thus completing the needed data set for the project.


We returned to the standing snag of the Tsali hemlock to complete the vegetation plots around the tree. We also gathered more detailed basal measurements to refine the existing data and standardize the volume with our current volume protocols.


Although it is sad to see the tree dead, the loss of foliage allows for a better view of the complex crown. This tree was likely very old, and of the trees we have finished canopy tree plots on, Tsali is surrounded by the tallest neighboring trees- up to 154’.



    The Tsali snag June 2006



< Jess setting up a basal reference.
Climb of the Jim Branch Giant, July 16th, 2006

The Jim Branch Giant was discovered in 2002 on a hunt for big and tall hemlocks. Hemlock woolly adelgid had just been discovered in the Park, and a new sense of urgency was instilled into the search. The Jim Branch Giant caught our eye not out of large size but incredible height. The tall appearance of the tree was enhanced by the lack of trees obscuring a view of nearly the entire tree.


Laser readings from 2002 gave a range of height of ~162 feet regularly but an occasional 167 foot reading would show up after many measurements. Perplexed by the wide range in height the tree was climbed in 2003 to perform a tape drop. Sure enough, the top of the tree was rather flat and had a “nested” top which was not easily hit by the laser bounces. Total tree height turns out to be 166.7’ which is the fifth tallest hemlock documented via climbing.

The tree was climbed again in July 2006 to obtain volume measurements. The tree was found to have the largest trunk diameter at 100 feet of any single-trunked tree (at 100’) we have yet climbed. Basically, for the first 100 feet the tree loses just fifteen inches in diameter. The relatively massive upper trunk coupled with the multiple trunks yield an extraordinary volume of 1188 ft3 for a tree only 13’1” in circumference!


This tree was treated in October 2005 and new growth had appeared in various places in the canopy. The decline in the surrounding trees after just four years of adelgid infestation was appalling. However, most trees had begun their second flush of new growth and all the trees surrounding the Jim Branch Giant have been treated as well. The trees treated in November 2002 looked like heads of rich green broccoli against the dingy gray of the untreated trees.
Climb of the Yonaguska Hemlock, September 9th, 2006

This tree has long reigned as the largest hemlock in the Smokies and was a subject of the documentary film, “Unspoiled Country” shot in 1999. During that filming it was measured to the incredible height of 168’11” making it the second tallest hemlock known. It was measured for volume in 1998 but the enormous fused section where two large stems originated posed a serious problem. We had employed some shortcuts which were less than ideal as viewed through the eyes of the Tsuga Search. Since the recent development of the frame mapping technique allowed us to more accurately measure such features we decided to climb the tree one more time to frame map the fused section before the tree falls. The tree died in 1999 presumably from a series of intense drought years, yet remained stable enough to perform one last climb.


It turns out the shortcuts we had taken in the first climb significantly overestimated the fused section. Jess and I set up four frame maps and determined the trees volume to be 1367 ft3, a full 35 cubic feet smaller than the previous climb suggested. The title of largest hemlock in the Smokies is now passed on to the Caldwell Colossus.


The Yonaguska Hemlock is a great example of how a non-exceptional trunk diameter can still amass serious volume if it possesses several critical components. This tree had it all wrapped into one- slow taper, extreme height and multiple trunks. We were fortunate to have found and documented the tree before it fell. It is also comforting to know the tree did not die an undignified death from hemlock woolly adelgid.

Climb of the Rough Fork Hemlock, September 14th, 2006


This tree has been on our minds since its discovery in 1996. It is growing in the flats filled with gorgeous old-growth hemlock just upstream of the campground on Rough Fork.  Although its estimated height was around 160’ the modest girth lead us to believe it too small for the Tsuga Search. However, a monocular assessment indicated a large upper trunk with slow taper so we decided to climb it. It turned out to be the sixth largest eastern hemlock documented in the Smokies to date!


Of particular note is the fact that this trees canopy is almost entirely composed of reiterations, resulting in one of the most complex crowns thus far traversed. It also proved to be a slow, tedious ascent as the tree was extremely thick with widely spaced limbs and twisted reiterations- at times full of large, loose debris fallen from above.



The top was dead and one leader was broken so it may have been taller in the past. Previous measurements from the ground indicated a height around 161’.

The view up Rough Fork and the surrounding ridges was devastating as adelgid induced decline and mortality was abundant. However, the Rough Fork Hemlock was full of new growth and had signs of recovery throughout the crown. NPS staff treated the tree on the same day as the climb.

Special thanks


We would like to take this opportunity to express our gratitude for the numerous volunteers and NPS staff members that have supported the Tsuga Search. Our work is made so much easier by these people, not the least of it by providing an environment of hope for the last vestiges of the ancient eastern hemlock forests. Our most sincere appreciation would go to the staff at Great Smoky Mountains National Park. The vision and support that Kristine Johnson and Tom Remaley have for this project is nothing less than phenomenal. Their assistance ranges from arranging additional field assistance to providing housing, good food and most exciting- partial funding. Of course, none of this would be possible without the direct financial backing and support of Will’s company, Appalachian Arborists, Inc. Many thanks go to co-owners Brian Hinshaw and Jason Childs for their endorsement of the Tsuga Search Project and field support.


The list…

Dr. Lee Frelich, University of Minnesota, for project advice,

Dr. Robert Van Pelt, University of Washington, for technical advice,

Robert Leverett for the assistance with the frame mapping calculations,

Robert Leverett and Monica Jakuc for setting up the ENTS for donations,

Ed Frank for posting updates to the ENTS website,

Muffi Brown for the tree core mounting board equipment,

Bob Weber for help on the climb of the Winding Stairs Loner,

Jack Romeyn for assistance on the Jim Branch Giant climb,

Josh Kelly for help on the Cheoah Hemlock plots and Buck Fork recon trip,

Carl Blozan for helping Jess on the Cheoah Hemlock vegetation tangle,

Jason Childs for the frame mapping help in the Cheoah Hemlock,

Jesse Webster and Mike Zumwalt for treating the Caldwell Colossus,

Dan Bryson for help with the Jim Branch Giant tree plot,

Wes Bintz for assisting on the Rough Fork Hemlock plot, and

Amanda Parks and Tina Köerner for help with treatments and plots on the Long Branch Hemlock.


We also extend sincere gratitude to the Highlands Ranger District for allowing for the treatment of the Cheoah Hemlock. The result of this simple action will become strikingly important in the coming wake of mortality from HWA. The losses of the great hemlocks will be more than devastating to all associated with the species. Having preserved what may be the largest eastern hemlock in existence is in and of itself remarkable, but in contrast to what little will remain in a few years it will be all the more important. The legacy of this single tree will be more fully understood as time goes on.



Will Blozan and Jess Riddle

Submitted October 12, 2006

[1] Except the Gabes Mountain Hemlock