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Redwood Hiking Summer 2017 – Redwood National Park

1      Helios Redwood, Redwood Creek Tributary

The tall trees lists have described the location of a number of tall trees in Redwood National Park as “Redwood Creek tributary”, including Helios.  There are a good number of Helios clues, and they all have some degree of helpfulness.  But to me, none made a specific location probable for Helios.  And on top of that there are no full views of Helios’ trunk on the internet.  Just bits and pieces, such as a small area of trunk burn marks and a small section of one side of the trunk.   And no canopy photos that show much.

But over the course of three years, with four visits to Redwood National Park searching for the tallest trees and quite a bit of time reading through research papers, viewing photos, and moving around Google Earth and Blue Marble I felt I had a good chance of finding Helios.


2      Hiking to Helios


I did not want to do the Helios hike alone.  So I planned the hike with two guys from the U.K, Carl and Phil, who I trust and are excellent redwoods researchers and hikers.

On a Sunday in August 2017 we took on this hike.  And it was quite an undertaking, ten hours of hiking in all.  And we were successful.

The approach to Helios is just what you would think for a tributary of Redwood Creek.  There is a creek and there are steep hillsides.  And both are filled with giant logs, some recent falls and many worrisome rotting logs from treefall one or two hundred years ago.  So over logs, around logs, under logs, along logs.  Logs, logs, logs.  Then throw in big ferns and nettles.  And rocks, big ones.  I fell three times, once off a rotten log, winding up on my back under some brush.  I had to wiggle my way uphill while on my back to get out of the thicket.  Carl and Phil took some spills as well.  One of us had a serious wardrobe malfunction to contend with on the hike back out.

Do not do this hike on your own!   Do not do this hike if you cannot tolerate extreme physical exertion!

Here are a couple views of typical redwoods and other trees and plants in the Helios area.  Lots of ferns and rhododendrons.  Also quite a bit of western hemlock, sitka spruce,  and bay laurel.   But the majority of the biomass is definitely redwoods.

Large redwoods above Helios’ creek


View looking down toward Helios’ creek


3      Finding Helios


The three of us had climbed up a hill and were spread out.  We noted a strong candidate, Phil got to the tree first and yelled “I think you will be very pleased with this tree” in the typical understated British way.  Then Carl had a good pic of the burn marks on his tablet and what we saw lined up exactly in every detail.   This was Helios, definitely.  And we got it confirmed the next day.

Here are two views of Helios similar to what has been on the internet.  The first is a section of the burn marks.   The triangle on the left is the official shark tooth.   Then the second is me in front of the trunk.

I cannot show any full trunk or crown views of Helios.

Helios shark tooth (on left).


Standing at the trunk of Helios.


4      Helios Height


We did put rangefinders on the top of Helios and got a ballpark height.   But we didn’t have prisms and tripods to get a definite height, and also didn’t find a ground level tag on the tree.

But Helios is immensely tall, perhaps as tall as Hyperion.   And Helios has a lot of character, lots of interesting and unique features.  That is what you would expect from a 2,000 year old tree.

Helios Was a 400 Foot Redwood Not So Long Ago


1      Hyperion and Helios

Disclaimer:  This analysis is based on my own interpretation of published redwood study information, primarily from this source:

How do tree structure and old age affect growth potential of California redwoods?

Stephen C. Sillett, Robert Van Pelt, Allyson L. Carroll, Russell D. Kramer, Anthony R. Ambrose, D’Arcy Trask

Ecological Monographs 2015 Vol: 85 (2) :181-212.
doi: 10.1890/14-1016.1

So here we go ….

Hyperion and Helios are remarkably similar redwoods in some ways. They both grow on steep slopes above Redwood Creek tributaries.  Their diameters and heights are very similar.  But there is one big difference – Helios is 2040 years old versus Hyperion is a sprightly 1260 years old.   Then also Helios has reiterations in its crown versus Hyperion does not.  A reiteration is regrowth after breakage.

I started to think, I wonder what the height of Helios was before its top broke off and grew back.  Was it once taller than its current height of 377 feet or so?

Well, I think it was taller, a little over 400 feet tall, and that was not so long ago.

2      Helios Height Estimate Before Reiteration


The idea is to review diameter at 80 meters in height for Helios and Hyperion, then for calculation purposes adjust Helios’ diameter at 80 meters downward a bit due to its greater age.

Then, take the amount of growth in Hyperion above 80 meters as a function of its trunk diameter at 80 meters.   This is then applied to the Helios diameter at 80 meters to arrive at a Helios height before reiteration.   Remember Hyperion has no reiteration in its crown.

Then to get the approximate date of the Helios reiteration take the Helios average change in height per year and apply this to the amount of height that is above the reiteration.

So we start with this table:

Tree Name Age Study Year Height Diameter cm at 80 meter height (est) Ring Width cm at 80 meter height (est) Diameter cm at 80 meter height age adjustment cm growth above 80 / cm diam at 80
Hyperion 1260 2010 115.62 163 0.065 0 21.9
Helios 2040 2013 114.82 198 0.048 -4

And from there do this set of calculations:

Hyperion cm growth above 80 m / cm diameter at 80 m 21.9
Helios original growth above 80 m based on Hyperion 4236
Helios height pre reiteration in meters (est) 122.36
Helios height pre reiteration in feet (est) 401.5
Helios reiteration point height meters 106.5
Helios actual reiterated growth meters 8.32
Helios growth rate per year centimeters (past 10 yrs) 9.2
Helios estimated age of reiteration in years 90.4

So it can be inferred there was at least one 400 foot redwood in the past, it was Helios.  The top was probably blown out during a major windstorm between 1900 and 1925.

Helios may be a 400 foot redwood once more, but that will take another 70 years or so.

If there is a 400 foot redwood again it will probably be Helios, Hyperion, or some other redwood growing on a bench on a steep hillside with relative protection from high winds.  Trees growing on flats along Bull Creek or Redwood Creek are probably too exposed to high winds to avoid breakage once they get a lot taller than the rest of the surrounding redwoods.

Then the other factor is the timing of the next Cascadia earthquake.  That will snap off a lot of the tops.

Thanks for reading.

Tall Redwoods Need Loads of Schist

1      Tall Redwoods and Creeks

There is an association between alluvial flats built up from by stream flood deposits and tall redwood trees.  The tall redwoods spread their roots through this nutrient rich soil, often in multiple iterations as alluvial soil builds up from flooding events over the centuries.   However these streams are not an important source of water for these redwood trees.  Instead high amounts of annual rainfall as well as year round fog drip provide the water for these giants.   However there is another way rich soil can accumulate to support the growth of tall redwoods.

2      Tall Redwoods and Schist Filled Benches

If you have been on the hillsides above redwood creeks you may have noticed several things.

  • First, the hillsides can be very steep, with gradients often between 20 and 40 percent.
  • Second, there are convex (slightly bowl shaped relative to the slope) benches that occur at different elevations on these hillsides.
  • Third, these benches have a dark, fine soil. That dark fine soil is called schist and when you stand on these benches you are standing on a pile of schist.   Schist is great soil to support redwood tree growth.    In the Redwood Creek Basin the soil on the hillsides (all of it) creeps about 2 millimeters per year and can also flow up to 200 millimeters during a very heavy rain event.  The convex shape of the hillside benches induces the capture of the creeping schist soil.  Presto, you have the perfect growing medium for a redwood.

If a redwood grows on a schist bench in an area that is within reach of fog year round it can grow very tall.  As tall as any redwood that grows in the alluvial flats.

Hyperion grows on a schist bench.  By all accounts Helios and Orion also grow on schist benches.

Much of the alluvial flat soil is schist that has washed, flowed, or crept down the hillside, mixed with the flowing creek, and then left on the flats above the creek banks as the waters receded.    To some extent this occurs every year during the transition from the wet to the dry season.  One type of schist soil is called greywacke.  There is a redwood on the upper Bull Creek flats in Humboldt Redwoods that is named Graywacke after this soil type.


3      Schist in Northern California Is Formed by Plate Tectonics


A lot of geology is hard for me to follow but apparently the schist associated with northern California redwood forests was induced by tectonic fracturing and shearing of underlying bedrock.  There is a tremendous amount of tectonic activity in the northern California redwood belt, as this is the location of the Mendocino Triple Junction where three large tectonic plates meet.   There is a subduction zone a short distance offshore which induces giant (9.0 magnitude) earthquakes every 300-500 years (the last one was in 1700).   Off the major faults are many minor faults, and the some of the notable redwood creeks follow these minor faults.  Examples are Redwood Creek following Grogan Fault and Lost Man Creek following Lost Man Fault.

The tectonic activity and associated periodic earthquakes have created the benches on the hillsides and contributed to the unstable nature of the soil formations.  The soil formations then  creep over time, allowing for the collection of the soil in the convex benches.

4      Schist in Northern California Needs Flooding for Active Transport


Heavy rains induce the hillside schist soils to flow over the underlying bedrock.  This can help the convex hillside benches “fill up” with soil as well as transport soil down to the creeks.  Once in the creek the schist soil mixes in with the fast moving floodwaters.  Then as the flood waters become less turbid and start to recede the schist falls out of solution and adds soil to the alluvial flats along the creek.


5      The Formula for Tall Redwoods in Northern California


A unique set of circumstances have combined to create the spectacular redwood forests in northern California.   These forests would not be as impressive or even exist at all if even one of these ingredients was missing:

  • High annual rainfall
  • Some fog to provide moisture during the dry season
  • Temperatures above freezing year round
  • Incredibly rich schist soils which are the product of tectonic activity
  • Flooding rainfalls to move the soil into the convex benches and build the alluvial flats

Forests with tall redwoods need earthquakes and floods to thrive over the millennia.


6      It is Difficult to Measure the Height of Redwoods on Hillsides


Exceptional redwoods have been noted and measured in the northern California redwood forests for over fifty years.  Looking through the data the redwood dimensions are defined in these ways:

  • Diameter (or circumference which we recall from trignometry is pi x diameter).  This is by far the easiest dimension to measure as you walk up to the trunk and use a tape wrap or rangefinder to do the measurement.
  • Height. This can be difficult as the top of the tree needs to be hit at a distance with a rangefinder, then the height differential between the measure point and the point where the trunk meets soil needs to be determined.
  • American Forestry Points:  Trunk circumference inches plus height in feet plus one fourth average crown spread in feet.  So here the crown spread has been added as an additional measurement to base circumference and height.
  • Mass or volume. This is exceedingly difficult to measure and requires multiple measure points along the trunk as well as some kind of estimate of wood in the limbs and branches.  Based on the overall shape of the redwood formulas for different geometric cone forms can be used as an estimate.

When a tall redwood is on a hillside all these measurements become more difficult.

  • For diameter the determination of average breast height (4.5 feet) measure point can involve some judgement as the point where the trunk meets soil can be ten feet higher on the up slope side of the tree versus the down slope side of the tree.
  • For height the elevation differential between measure point and trunk elevation can become difficult. Many hillside redwood tops will measure around five hundred feet in height from a measure point on the flats but how high is the tree base above the flat?   The GPS can become a little erratic on a remote forested hillside and GPS altitude  readings are usually a little off.  So even if you get coordinates right at the trunk that may or may not be correct for altitude.

Also LiDAR has had its problems measuring trees on slopes.   If a tree leans to the downhill the height will be overestimated.  But there are also many redwood trees that lean a little uphill.  This is due to the downslope buttressing seen in many hillside redwoods.   Redwoods leaning uphill will have an underestimated LiDAR height.  By the way, this hillside buttressing is an area of controversy in determining the ground level for hillside redwoods.

Demonstrated LiDAR errors for redwoods heights are up to five percent.  This would result in an 18 foot or so error for a very tall redwood.

It is possible the tallest redwood is not Hyperion but rather a hillside redwood that has been missed so far.   It is very easy to walk right by a tall hillside redwood.  There is a chance a redwood or two growing out of a schist bench on a steep hillside slope could be taller than Hyperion.  As one redwood explorer has commented, “chance has potential”.

7      Views of Tall Redwoods Growing on Schist Filled Hillside Benches


Tall redwoods growing on schist filled bench above Redwood Creek tributary
Tall redwoods growing on schist filled bench above Redwood Creek tributary


Tall redwoods growing along schist filled bench above Lost Man Creek
Tall redwoods growing along schist filled bench above Lost Man Creek


8      Views of Tall Redwoods Growing on Schist Filled Alluvial Flats


Harper Flat. Even aged forest of tall redwoods with many fusions. Fused redwoods are clonal sprouts from same roots that fused over time as the trunks touched and grew. Even age of stand and clonal fusions due to flooding event 1,000 years ago.
Harper Flat. Even aged forest of tall redwoods with many fusions. Fused redwoods are clonal sprouts from same roots that fused over time as the trunks touched and grew. Even age of stand and bias toward clonal propagation  due to flooding event 1,000 years ago.


Redwood National Park Tall Trees Grove. Iconic alluvial flats grove.
Redwood National Park Tall Trees Grove. Iconic alluvial flats grove.