Tag Archives: Redwood National Park

Tall Trees Grove in Redwood National Park

1       Formation of Tall Trees Grove

There is not much published research on the age of the northern California redwood forests.  Redwood trees have been on Earth for millions of years in various forms.  The coast redwoods that grow along a narrow belt from Big Sur to extreme southern Oregon are a remnant of the ancient redwood populations.  It is thought they were almost wiped out at the peak of the latest ice age, with only a few groves surviving in canyons around Big Sur.  But then as the glaciers retreated, the jet stream and Pacific inflow moisture shifted northward 400 miles.  The redwoods followed, establishing their present range.

From this we know the Tall Trees Grove cannot be more than 12,000 or so years old.  Whether it is 4,000, 8,000, or 10,000 years old, I don’t know and have never seen anything speculating on the age of the forests in Redwood National Park.   Given redwood trees live to 1,000 to 2,000 years of age it can be estimated there have been at most eight generations of redwoods in this grove.

2       Human History of Tall Trees Grove

Native Americans have lived in the Redwood National Park area for several thousand years.  Again, I have not read anything more precise, so from that will go with 10,000 years.  In the most recent times, just before European settlement, about five hundred Native Americans identified as the Chilula tribe lived on the northeast side of redwood creek near the inflow to the Pacific Ocean.  Some of the open berry fields on the first part of Redwood Creek trail going south were probably maintained by the Chilula through controlled fires.  In the summer the Chilula hiked south along Redwood Creek and then through Tall Trees Grove and up a trail to the Bald Hills.  This indicates the trail from the Tall Trees Grove parking area to the Tall Trees Grove is substantially an improved Chilula foot path.

3       Identification of Tall Tree and Establishment of Redwood National Park

In 1963 Paul Zahl and his family spent the summer around Prairie Creek Redwoods State Park.  Zahl was employed by National Geographic Society and tasked to document the redwood parks and to look for new areas with very tall redwoods.  At some point in 1963, Zahl was sitting on a hill across from the south part of Tall Trees Grove, and noted a very tall tree in the grove.  Surveyors were hired and the tree was measured at 368 feet.  It was on Arcata Redwood Company land.  The president of that company, Howard Libbey, pledged not to cut the grove while plans were being made for the establishment of Redwood National Park.  There was a lot of back and forth as to the location of the park but eventually the Redwood Creek watershed won out and the park was established five years later. 

There is a little bit of intrigue associated with the actual tallest tree in the 1960’s.  Correspondence exits between Paul Zinke (Humboldt Redwoods area researcher) and Rudolf Becking (Redwood National Park area researcher) regarding possibly taller trees at the confluence of Bull Creek and Eel River in Humboldt Redwoods State Park.  But it was decided to keep the issue low key to help get Redwood National Park established.  Google “letter from Paul Zinke to Rudolf Becking” and follow the results to see a copy of this 1966 letter.

4       Tall Trees Grove Logistics

It is well documented on the park web sites a certain procedure needs to be followed to access Tall Trees Grove.  The visitor center just south of Orick or the one in Crescent City provide permits to use the Tall Trees Grove access road along with the combination for the locked gate that sits at the entrance of the access road. The access road is a maintained old logging road and heads south from Bald Hills Road just past the Redwood Creek overlook to the Tall Trees Grove parking lot on the hill above Redwood Creek.  Be sure to shut and lock the gate after pulling through and drive the six or so winding miles on the unpaved road at a moderate pace to keep the dust down and the stones out of your wheels. The trail from the hillside parking area down to Tall Trees Grove is not difficult but it is steep coming back up, about 700 feet elevation gain in a little over a mile.  There are five or so rest benches along the trail.

Some people camp along Redwood Creek a short distance from Tall Trees Grove.  If you are doing this let the ranger know when getting your Tall Trees Grove permit, you will then receive a bear proof cannister for your food.  There are a lot of black bears in the Tall Trees Grove area that eat fish, frogs, crustaceans and the bark of young redwoods.  Then there are also mountain lions which follow the deer down to the creek.

5       Tall Trees Grove Itself

Tall Trees Grove itself it not large. The flat with the tallest trees is about 30 acres then there are another 100 or so acres of mixed old growth forest on the hillside. However there is a high density of very tall redwoods. The grove has four of the fifty tallest trees in the world (National Geographic (Nugget), Paul Zahl, Howard Libbey (Tall Tree), and the Redwood Creek Giant.

The grove also has a nice Big Leaf Maple forest right by the creek.  It is possible these maples are in a part of the grove that is subject to flood inundation.

In the summer when the water is low the gravel bars along Redwood Creek can be accessed to provide views of Tall Trees Grove and the surrounding area.  This is the most special and scenic part of seeing Tall Trees Grove.

On the hike up take time to appreciate the hillside forest, noting the large redwoods all along the trail as well as tall Douglas firs higher up.  There is a nice rhododendron bloom on this trail in June. Thanks for reading.

Rhododendron on hill along Tall Trees Grove trail
Hillside Douglas fir fallen over Tall Trees Grove trail
Redwood NP Tall Trees Grove north side from Redwood creek
National Geographic Redwood, a trail side tree in Tall Trees Grove

Easy and Scenic Redwoods Hiking – The Great Northern Redwood Parks From South to North

1      Hendy Woods

 Hendy Woods is about 125 miles north of San Francisco.  Do a rest stop in Cloverdale, the driving west on Route 128 is windy and slow for a while, but then things level out when the scenic Anderson Valley is reached.  Hendy Woods is small but has some big and tall redwoods, a few above 340 feet in height.  The loop trails are easy level hiking.

Hendy Woods from Navarro River
Hendy Woods upper loop trail

2      Montgomery Woods Reserve

Montgomery Woods is 30 winding miles north of Hendy Woods.  This is a pretty famous redwood park.  It has a couple trees that are in the top 20 in height among all redwoods.  There is a short hike from the parking lot to the grove that has a pretty good elevation change but is very doable if a measured pace is followed.  The trail is very nice, looping around both sides of the grove and allowing hikers to walk right among the tall trees.

Montgomery Woods Reserve natural earthen dam
Montgomery Woods upper flat

3      Richardson Grove

Richardson Grove is about 100 miles north of Montgomery Woods.  The short drive through this grove along 101 is spectacular.  Slow down and enjoy it.  The tallest redwoods in the park are at the visitor center and are about 340 feet in height, but there are a bunch of big and tall redwoods right along 101.

Richardson Grove visitor center deck trees
Richardson Grove tall redwoods at visitor center

4      Humboldt Redwoods

The heart of Humboldt Redwoods is about 40 miles north of Richardson Grove.  The Founders Grove and nearby Rockefeller Loop have very nice mostly level trails, with a number of trees over 360 feet tall. 

Humboldt Redwoods chaos at Dyerville Giant
Humboldt Redwoods Rockefeller Loop

5      Redwood National Park

Redwood National Park is about 100 miles north of Humboldt Redwoods.  The tallest trees in the world grow in the remote Redwood Creek Valley and are 380 feet tall.   However if you want to drive deep into a big redwood forest with easy hiking do the Lost Man Trail.  There are big trees in Lost Man as well as a few over 350 feet tall. Another good Redwood National Park trail near Klamath is up Flint Ridge, it is well constructed and the climb is scenic and gradual.

Redwood National Park Lost Man Trail
Redwood National Park Flint Ridge

6      Prairie Creek Redwoods State Park

Prairie Creek Redwoods is just north of Redwood National Park and has many trails through fine redwood forests.  The great trail network starts at the visitor center and there are also a lot of trails accessible along Drury Parkway and Cal Barrel Road. Lots of the largest (by volume) redwood trees are in Prairie Creek.  The trails near Prairie Creek are relatively flat and then there are some trails going up the hillsides that have nice gradual ascents.

Prairie Creek Redwoods near visitor center
Prairie Creek Redwoods Irvine Trail

7      Del Norte Redwoods State Park

The heart of Del Norte Redwoods is about 20 miles north of Prairie Creek Redwoods.  There are few trails and they are pretty steep.  The section of the Damnation Creek trail from 101 to the old Coastal Highway is steep but not very long, the climb out is not a problem.  The old Coastal trail at the Damnation creek intersection is very scenic and follows the outline of a big canyon.

Del Norte Redwoods Coastal Trail

8      Jedediah Smith Redwoods State Park

Jedediah Smith Redwoods is about 15 miles north of Del Norte Redwoods.  The Boy Scout trail goes from the east to west end of the park.  It has a couple small hills and is about a five mile hike out and back.  It is well worth the time and effort, don’t make a race of it and keep your eyes open for many big redwoods, some right along the trail.

Jedediah Smith Redwoods Boy Scout trail eastern section
Jedediah Smith Redwoods Boy Scout trail western section
Jedediah Smith Redwoods Boy Scout trail western end

Thanks for reading.

Redwood Thunder

1      Redwood Thunder

Redwood thunder is an uncommon but not rare event. It occurs when a large redwood tree falls to the forest floor, sometimes striking and taking other redwoods, firs, spruce, oaks, and maples with it. A cubic foot of redwood weighs 50 pounds, so if a moderately large 20,000 cubic foot redwood topples that is a million pounds, or 500 tons of wood crashing to the earth.

For redwood thunder to occur usually soaked soil and wind are required, though if the tree fractures on itself soaked soil is not an ingredient.  Sometimes before redwood thunder occurs the tree will lean against an adjacent tree, with the trunks and branches rubbing with the wind and making screeching sounds like giant stringed instruments.

All redwood trees eventually topple, or at least break off down to a low point on the trunk.  If a given old growth redwood has a one in a thousand chance of falling in any given year than that means, based on acres of old growth redwoods, the average annual tree fall count in the large redwood parks is about 300 trees, per park.

If there are multiple trees involved in a tree fall or if the tree falls across a creek, the tree fall is noticeable in Google Earth.  If you hike the same trails over several years you will for sure see trees that have recently fallen.  Their upper trunks are huge and their logs run sometimes more than a football field along the forest floor.


2      Examples of Tree Falls


Here are several examples of tree falls I ran across in 2016.  Included are a picture I took of the tree fall accompanied by before and after Google Earth views of the tree fall areas (using Google Earth historical imagery).

In Humboldt redwoods a neighbor of the big Dyerville Giant log fell in the late spring 2016.  Its trunk shattered and splintered into sections where it struck the Dyerville Giant log.

Tree fall across Dyerville Giant in Founders Grove
Tree fall across Dyerville Giant in Founders Grove


Founders Grove - tree to fall marked with X. (Image from Google Earth)
Founders Grove – tree to fall marked with X. (Image from Google Earth)


Founders Grove - space left by fallen tree marked by X. (image from Google Earth)
Founders Grove – space left by fallen tree marked by X. (Image from Google Earth)


Another recent tree fall in Humboldt was in the area where a seasonal foot bridge is put in to link the Rockefeller Redwood area to the Giant Tree area on either side of Bull Creek in the upper Bull Creek Flats.  The new big log is used a lot to cross the creek, though it would be a pretty tough eight foot or so fall from the log to the rocky creek bottom if your foot or the bark slipped.

Log across Bull Creek in Giant Tree area
Log across Bull Creek in Giant Tree area


Bull Creek Giant Tree area - tree to fall marked with X. (Image from Google Earth)
Bull Creek Giant Tree area – tree to fall marked with X. (Image from Google Earth)


Bull Creek Giant Tree area, empty area where fallen tree was standing marked with X (Image from Google Earth)
Bull Creek Giant Tree area, empty area where fallen tree was standing marked with X (Image from Google Earth)


A third fall in Humboldt occurred in Harper Flat.  The tall north side of a twin trunk redwood fell in the last couple years.

Harper Flat fallen tree, north side of pair (still from I Phone video)
Harper Flat fallen tree, north side of pair (still from I Phone video)


Harper Flat - tree to fall marked with X (Image from Google Earth)
Harper Flat – tree to fall marked with X (Image from Google Earth)


Harper Flat - area left by fallen tree marked by X (Image from Google Earth)
Harper Flat – area left by fallen tree marked by X (Image from Google Earth)


The final example is in an area of tall hillside redwoods on the east side of Redwood Creek a little north of McArthur creek near the seasonal foot bridge.  Here the tree fall took out a number of redwoods and the whole group of fallen trees is slowly sliding down toward Redwood Creek.

Redwood Creek tree fall area, trees are slowly sliding downhill.
Redwood Creek tree fall area, trees are slowly sliding downhill.


Redwood Creek hillside above north seasonal foot bridge, trees to fall marked with X (Image from Google Earth)
Redwood Creek east hillside above north seasonal foot bridge, trees to fall marked with X (Image from Google Earth)


Redwood Creek east hillside above north seasonal foot bridge, area where trees stood marked with X (Image from Google Earth)
Redwood Creek east hillside above north seasonal foot bridge, area where trees stood marked with X (Image from Google Earth)

3      What Can Be Learned From Fallen Redwoods


A recently fallen redwood is a great opportunity for whole tree research once the soil in the fall area has stabilized.   The root system and affixed soils can be studied without any digging, this is the big primary benefit.  But also core samples can be extracted without having to climb and core living trees.  The canopy structure can be measured and reviewed without climbing and an unlimited amount of destructive sampling can be done.

Thanks for reading.

Distribution of Tree Height in an Old Growth Redwood Forest

1      Old Growth Redwoods


Old growth redwoods – that phrase invokes a lot of different feelings in people. Certainly in the present the phrase describes the large never cut forests in the redwood parks. Forests full of giant trees, some by rivers or streams and others along hillsides. Forests covered with needles and sorrel and forests covered with ferns. Forests with deer moving through them to reach the creeks, all the while shadowed by mountain lions. Forests with black bear dens. Remote and rugged but never more than a few miles from a highway.

Two parks with many acres of old growth redwoods as well as the ten tallest trees in the world are Humboldt Redwoods State Park and Redwood National Park.   Each parks contains hundreds of thousands of old growth redwood trees.   Here is the math:

Park Acres Old Growth Redwoods # Redwood Trees > 100 cm per Hectare # Acres per Hectare # Old Growth Redwood Trees
HRSP                    17,000 50 2.47                            344,130
RNP                    19,640 50 2.47                            397,571


The redwood density figure is a general rounding of the findings in a redwood plots study underway at Humboldt State University.

If that number seems too high, well…. Here are two pictures.   These are from the Redwood Creek Overlook on Bald Hills Road in Redwood National Park.   The old growth forests and patches are very distinctive.   If you go to that overlook and put a strong pair of binoculars on those forests it is an impressive site.   Many big and tall trees all growing along Redwood Creek and the surrounding feeder creeks and hillsides. I can’t imagine a more spectacular forest. It is kind of intimidating.

Redwood Creek Overlook looking west northwest.
Redwood Creek Overlook looking west northwest.


Redwood Creek Overlook west southwest view
Redwood Creek Overlook west southwest view


2      Height Distribution for the Tallest Trees


Thorough ground based searches combined with LiDAR technology have given a pretty complete picture of tree height in all parks with the exception of the Headwaters Reserve. The tallest redwoods, those over 365 feet, are all in Humboldt Redwoods State Park and Redwood National Park, with the exception of two trees in the exceptional Montgomery Woods Reserve. Then all the trees over 370 feet (there are only ten or so) are in Humboldt Redwoods State Park and Redwood National Park.


Trees over 350 feet.  Each line represents a tree.
Trees over 350 feet. Each line represents a tree.


There are two things that are apparent when viewing these graphs. First, the distribution patterns are very similar between the parks. And second, there are a lot more tall trees in HRSP than in RNP. Based on this data paired with the history of each park the explanation is certainly this: In Humboldt most of the forests with the tallest trees are intact. In Redwood National Park most of the forests with the tallest trees have been thinned or removed.


3      Height Distribution for Old Growth Redwood Trees


Noting the steepness of the curve on the tall trees graph it is evident there is some type of “bell shaped” distribution where there are many trees of a certain height, say 350 feet, then the trees get fewer and fewer at 360 feet and even more scarce at 370 feet.

Using this information and the total number of old growth redwoods we can infer the number of trees of certain heights:

Std Deviations Expected Pct of Trees Less Than HRSP Expected Trees RNP Expected Trees HRSP + RNP Expected Trees
2 97.725%                      7,829                      9,045                              16,874
3 99.865%                          465                          537                                1,001
4 99.997%                            11                            13                                      23
4.5 99.99966%                              1                              1                                        3
5 99.99997% 0.0981 0.1133 0.21

Looking at the results of expected trees versus actual tree populations, it is evident four standard deviations describes 368 feet or so redwoods, while 4.5 standard deviations describes the very tallest redwoods (380 feet).

Then with some calculations and interpolation, we can arrive at three standard deviations corresponding to a 338 foot redwood tree.   This then results with the following very approximate distribution of tree height in old growth redwood forests in Humboldt Redwoods State Park and Redwood National Park.

Std Dev Height Feet
4.5 383
4 368
3 338
2 308
1 278
0 248
-1 218
-2 188
-3 158
-4 128
-4.5 113


So the average old growth redwood in Humboldt and Redwood NP is 250 feet tall.  Remember this covers all old growth trees at all elevations that are at least 3.28 feet in diameter.

Then there are 1,000 trees over 338 feet in height.

What do you think?


4      Old Growth Redwood Groves Close Ups


For some closer in views of old growth, here are pictures from two of my favorite areas in the redwood parks.   There are views like this all over the redwood parks.


Humboldt Bull Creek outflow
Humboldt Bull Creek outflow


Redwood NP Lost Man Creek area
Redwood NP Lost Man Creek area


Thanks for viewing and reading.


How Tall and Large Can Redwoods Grow


1      Maximum Height of Redwood Trees

Over the past twenty years the redwood groves on public lands have been systemically surveyed for tree height using both ground based rangefinders as well as airplane based LiDAR pulse measurements. The resulting point in time data has identified 220 individual trees at or over 350 feet in height on public lands.   It is possible there are a few other trees over 350 feet on private lands (half the remaining old growth redwood forest is on private land but the public lands generally have the better redwood habitat).

This is a graph of the distribution of height for these trees.


Distribution of height for 220 tallest redwoods
Distribution of height for 220 tallest redwoods


As you can see redwoods over 360 feet are rare, just 51 trees. And redwoods over 370 feet are exceedingly rare, just 8 trees. Then the two tallest trees are about 377 and 380 feet in height.

There apparently are factors in play that are limiting tree height. From the demonstrated heights the trees have a hard time obtaining 370 feet. There are several studies on theoretical redwood maximum height that have come up with heights a little over 400 feet. These studies take into account the energy required to draw water up to the top of the tree as well as the water which can be extracted from atmospheric fog.   However there are no trees now in excess of 380 feet.

While it is true what remains is just five percent of the original redwood old growth the parks themselves are in some of the best areas for big and tall trees. Also many of the parks have been around for quite some time now, and in some cases there is a fifty year growth record that can be referenced for some of the tallest trees.   For example in 1964 National Geographic published research on very tall trees along Redwood Creek in the area that became Redwood National Park. At that time the three tallest trees in that area were 364 – 368 feet in height. In the fifty years since 1964 none of these three trees have reached 370 feet in height. There is a physiological limiter on tree height that seems to be around the 370 foot mark.

As another example, the Humboldt Rockefeller forest is noted as having many of the tallest redwoods. This forest has been protected for over eighty years. At this point in time no tree has reached 375 feet in that old growth forest. There are dozens of trees over 360 feet in the Rockefeller forest area but none have reached 375 feet. Again some type of physiological maximum appears to exist for tree height around the 370 foot mark.

2      Example – Humboldt State Park 373 ft Redwood


To review a specific tree, let’s take a look at this 373 foot redwood.   This is a magnificent tree in the Humboldt Rockefeller forest whose most recent published height measurement is 372.73 feet. As you can see it also has a large diameter – over 17 feet.   Based on lists of the largest redwoods, this is the largest volume redwood of those over 370 feet.

Base of 373 foot redwood. Diameter is over 17 feet
Base of 373 foot redwood. Diameter is well over 17 feet

When I found this tree in the forest I immediately knew what tree it was and it just took my breath away. It is an impressive tree in an incredible forest setting.

Who is that tiny guy in the forest


View up toward the crown
View up toward the crown


The first published height for this tree, shortly after it was identified as one of the tallest trees, was 368.6 feet in 2000.   Then the most recent published height was 372.7 feet in 2013. So that is a growth rate of 4.1 inches per year or one foot every three years. So does that mean this tree can get to 380 feet in twenty years and 400 feet in eighty years?  I would say 380 feet is a good possibility but 400 feet is a stretch.

3      Example – Redwood National Park 371 Ft Redwood

This beautiful tall redwood grows on a bench along Redwood Creek. It is another one of the extremely rare 370 footers – the latest published height I have found is 371 feet from 2013.

This tree could not be in a more pleasant setting.

Published measurements over time indicate this tree has grown about eight feet in the last fifty years. This works out to be two inches per year.  In recent years the height gain per year has been more than the fifty year average. Does that mean this tree will be a 380 footer in a few years and a 400 footer in thirty years?  Again 380 seems possible, even probable, and 400 would be a stretch.  There is no confirmed record of a current or historic 400 foot redwood tree.


371 foot redwood in Redwood National Park
Trunk of 371 foot redwood tree in Redwood National Park


371 redwood tree and its neighbors. Standing tall along the bench like the Golden State Warriors
371 redwood tree and its neighbors. Standing tall along the bench like the Golden State Warriors


It is possible factors could be in play to increase or decrease redwood growth rates.   For example the increase in atmospheric carbon could be helping the forest get taller as there is more energy provided for photosynthesis. Or if there is a decrease in foggy summer mornings that might have a negative effect. These types of changes are being evaluated and quantified by current redwoods researchers.

Also any tree that gets high above its neighbors has a top that is less protected from wind. All the tallest trees will eventually lose part of their crown to wind. However they could still keep on adding wood to their surface area over time, allowing them to become the largest volume redwoods. And it is possible their crowns could “reiterate” (grow back) after breaking off.

So how tall can a redwood tree grow?   My guesstimate is 400 feet.

4      Maximum Volume of Redwood Trees

It is more difficult to assess the volume of a redwood tree than to measure its height. Trees have different shapes at the bottom and then taper off at different rates as height increases. Then the volume of the branches and limbs needs to be taken into account as well.

As a rule of thumb the volume of a redwood can be estimated using the formula for the volume of a perfect cone.   It works pretty well for some of the big volume redwoods:

Large tree volumes versus cone formula

In the last five years no new tallest redwoods have been identified.   But there have been some new top ten largest redwoods found and preliminarily measured.   There are areas of the redwood parks that have not been fully explored for the largest redwoods. Generally these are off trail hillside areas in the northern redwood parks.

There are also some differences of opinion on what to include for volume when a redwood tree has a complex trunk with partial fusions. This is particularly true for the two largest trees listed above.

This is a point in time distribution of the thirty largest by volume redwoods. It is incomplete because not all the redwood range has been surveyed for volume and new discoveries are being made.

Distribution of volumes among largest redwoods
Distribution of volumes among largest redwoods

As you can see there are very few redwoods over 35,000 cubic feet. It is possible a few historic redwood trees may have exceeded 45,000 cubic feet and rivaled the 52,500 cubic feet in the largest known living tree – the General Sherman sequoia. Possibilities are the Crannell Creek Giant and Lindsey Creek tree.     There is more unknown out there for tree volume, the current profile of top redwood trees by volume is not as complete as the profile of top redwood trees by height. It’s just harder to come up with a volume measure for a redwood, although if diameter and height are known a volume range can be inferred.

5      Humboldt Largest Redwood


The largest known volume redwood in Humboldt is about number ten on the list of the largest redwoods by volume. It is a powerful presence in the forest.

Largest volume Redwood in Humboldt
Largest volume Redwood in Humboldt

It sits in a forest growing on an alluvial flood plain. This tree lost maybe thirty feet from its top decades or centuries ago. At one time it was probably one of the tallest trees but now has aged into one of the largest ones.

Forest surrounding largest tree in Humboldt. Many, many big, big trees.
Forest surrounding largest tree in Humboldt. Many, many big, big trees.

A large volume redwood probably adds more wood per year than a tallest redwood since it has more surface area to cover. I am sure attempts are being made to measure redwood volume over time. A new technology I have noticed here and there are ground based LiDAR sensors tied into remote power generation stations. This would be an effective way to use technology to measure something that is difficult to measure.

So how large can a redwood tree become? The current maximum is around 45,000 cubic feet, there may have been a few larger than that in the past. And in the future there could again be 50,000 cubic foot redwoods.  No doubt.

Thanks for reading.