Topic ID #3543 - posted 6/4/2008 2:10 PM

Juniper trees and stone rings


This is a topic more oriented to those working in the western plains states.

Anyway, I just recently finished a survey of a very large archaeological site in central Wyoming. The site was located on a large ridge south of the Bighorn Mountains and the entire ridge top was covered with a dense scatter of glacial outwash rocks from the Bighorns. The ridge also had a prolific growth of junipers all over the place. We ended up recording over 160 stone features. On the last day, we were finishing up and encountered a group of junipers. Around the base of each juniper was a perfectly formed stone ring. It certainly appeared the juniper trees roots had "pushed" the rocks outward from the base of the trees as they grew. The soils I might add were relatively shallow, well drained and very, very rocky. Many of the "pushed" rocks were of the typical size we find forming stone (or tipi) rings out this way.

If the junipers we observed had indeed formed these stone rings at the base of the trees, the question then arose, how many of the 100+ stone rings we had recorded were cultural or natural? Over time, when the juniper dies and the truck base decays away, all that would be left would be the stone ring, assuming the tree roots had pushed the rocks outward from the tree base. In the absence of associated cultural materials, how would anyone know if a stone ring was natural or cultural?

Now, I have recorded literally hundreds of stone rings over the years. The stone rings we observed around the base of those junipers certainly looked real, but given the extremely rocky soils on the ridge, it definitely appeared the tree roots had "pushed" these rocks outward to form stone circles.

Has anyone ever encountered such a thing before? Does anyone know of any literature discussing this phenomenon?

I have consulted some biologists and they have not observed such a thing, tho they have also not ever seen a stone ring either.

Any ideas?


Post ID#8479 - replied 6/4/2008 5:31 PM

John Brogan


I've spent time doing surveys southeast of Riverton, and we recorded lots of stone rings, most along ridges. None that I remember had juniper growing in them. I'm wondering if the ones you found weren't taking advantage of soil and moisture collecting in the rings. I know I was able to spot prehistoric walls in Arizona by the vegetation they seemed to attract. Just my 2 cents worth!


Post ID#8480 - replied 6/4/2008 5:33 PM


Sorry I can't help you but it is funny.
So, the Big Horn medicine wheel is the result of a hugh juniper? Who new?

Post ID#8484 - replied 6/4/2008 6:08 PM


Your question is interesting to say the least. If I was you, you might want to present a paper on this at a conference of your findings. I have seen small rings under brushy trees without charcoal staining and thought these could be the result of old trail markers because there was an apparent trail near by.

In Nevada I talked to an old Timbisha Shoshone Shaman once who claimed in the old days his father would put a large stone or rock in the fork of a pinion or juniper tree to mark a trail to follow. He later pointed a couple of these trail markers out as we were surveying the area that was embedded into the tree like he described. But it would take way to many rocks falling out of a tree to make a ring.

By the way thinking back Jamey over at TRC Mariah in Laramie, Wyoming when I was there in 2006 mention that he thought some stone rings were caused by tree stumps and roots pushing rocks in some places in Wyoming. Exactly the way you (Scott) are describing how the roots are pushing the rocks out in a large ring shape. Jamey also noted that most of the rings that were being recorded as true tipi rings had no artifacts in the deposits. That year we recorded a large tipi ring site on a ridge south of Rawlins about 20 miles on a gridded seismic survey many of the rings did not have artifacts but some did.

Post ID#8489 - replied 6/4/2008 8:29 PM


Here is a photo of an example of what we encountered at this site. All of the junipers in this stand of trees have similar "rings" around the base of the trees. The rings range in size from 3 m to 6 m in diameter.

This is at an elevation of about 6500 ft amsl.

After I posted this topic, I was reading thru a siteform for a bison kill/processing site located at the base of this ridge and outside of our project area. The site had 97 stone rings recorded for it and tucked away on page 91 of the site form was a one sentence mention that many of the rings had junipers growing in the center of them. An extensive lithic scatter is associated with this bison kill/processing site, but very, very few of the lithics are associated with the rings. So apparently the association of junipers and stone rings in this area is not uncommon.

Of the 100+ stone rings we did record at this site from which the photo below was taken, there were only 4 or 5 that had "remnants" of a juniper tree trunk in or near the center of them. In writing those up, I noted the presence of the juniper trunks/stumps and stated there was the possiblity the stone rings may not be cultural. None of those features had lithics associated with them either. The remaining rings all appeared to be real, but then who knows? Several of the rings we did record were located near stands of junipers, looked very real, had no lithics associated with them and did not have evidence of junipers having grown within them. Were they real or the remnants of a juniper "root push" of a tree that had long ago died and the base of the truck had decayed?

And no......I am not suggesting that medicine wheels are created by junipers. Medicine wheels typically have spokes which is something I find hard to believe a juniper "root push" could have formed.

Post ID#8490 - replied 6/4/2008 8:36 PM


Here is another view of the same juniper.


Post ID#8492 - replied 6/4/2008 8:46 PM


Nice photos. Now you have to go back and get tree ring samples to date the trees, they are part of your features.

Post ID#8493 - replied 6/4/2008 8:53 PM


Is it really a ring rather than just the outside of the circular duff of the the tree? It doesn't look like the rocks are much (or any) more concentrated in the ring than they are elsewhere that isn't under a tree.

Post ID#8494 - replied 6/4/2008 9:00 PM


Well...we did not these as features. There were no cultural materials in association. and I just am not convinced they are cultural. I want to point out that ALL of the junipers in the background have similar rings around the base.

And scalpcreek: I do not believe the NA used these as "center poles" for lodges or other purposes. Tipis did not have center poles to support their lodges. The poles were stacked to lean inwards and met at the top of the center of the lodge. They then supported the outer lodge covering. Ethnographically, medicine wheel spokes represent the lodge poles of a tipi.

Here is another image of two adjoining rings around junipers. I have highlighted the perimeters.

Post ID#8495 - replied 6/4/2008 9:05 PM


Is it really a ring rather than just the outside of the circular duff of the the tree? It doesn't look like the rocks are much (or any) more concentrated in the ring than they are elsewhere that isn't under a tree.

There is very little duff on the ground. Surface visibility is quite good. What does not show up very well in the photos perhaps is that there are no rocks larger than the ring rocks around the perimeter. The few rocks within the interior are more like gravels and smaller.


Post ID#8499 - replied 6/4/2008 9:44 PM


I have to agree with Desert Rat. I think this is some sort of natural process, probably, as previously pointed out affiliated with the root system. From what I can see, there is a slight grade change from the rock ring up to the tree trunk, within the "dripline" so to speak. I wonder if this "duff" is just obscuring the ground. Basically, like a rub-out picture; the area under the tree canopy is somewhat sheltered and the areas between are exposed-even wind would funnel through these areas and strip away (rub-out) light surface sands and what not.

I don't know, just hazarding a guess. Interesting none the less. I'll have to check out my area and see if this is happening with other trees as well.

Post ID#8500 - replied 6/4/2008 10:56 PM


PostPosted: Wed Jun 04, 2008 7:44 pm Post subject: trees
I have to agree with Desert Rat. I think this is some sort of natural process, probably, as previously pointed out affiliated with the root system. From what I can see, there is a slight grade change from the rock ring up to the tree trunk, within the "dripline" so to speak. I wonder if this "duff" is just obscuring the ground. Basically, like a rub-out picture; the area under the tree canopy is somewhat sheltered and the areas between are exposed-even wind would funnel through these areas and strip away (rub-out) light surface sands and what not.

PostPosted: Wed Jun 04, 2008 7:22 pm Post subject:
So, looking at the rock rubble scattered elsewhere in the area, it looks like you have 'cleared areas' more than rock rings. But you still have the "are they cultural" question. I sympathize. If I were in your place and I saw a ring-shaped clearing around every juniper, I'd be thinking that some noncultural mechanism is at work.


OK...first of all: There is no duff around the base of these junipers. I know that does not show up well in the photos, but I know what duff is and there is little to no duff present. Yes, the larger size rocks are nearly absent from the "dripline" area around the base of the junipers (thanks for that term--I could not think what that was called tho I have used it slipped my mind). And yes, as Bob pointed out, the dripline areas around the junipers appear to be "cleared out", whether naturally or culturally. I fall into the "naturally" camp.

This site is located on a ridge that is nearly 7.5 miles long with associated finger rides, each of which extend outwards for 0.5 to nearly 2 miles out. All of the ridges are fairly narrow and fringed with junipers. Where the finger ridges radiate out from the main ridge, there are wide open areas where the junipers are now growing prolifically. My photos I have posted are from this type of area. Whether this was the case back in prehistoric times I do not know.

And yes I agree the photos are showing "rings" that have been formed from natural processes. The thing is this: The previously recorded rings plus the ones we recorded total over 300+ rings. Most are real, but some are not. That is the point. Another site located at the base of this ridge had 97 stone rings and the site form for it noted "many had junipers growing within the rings", but no associated artifacts (and the exact number of those rings was not noted). That site is now listed on the National Register.

I am just pointing out, that in this area, not all stone rings are cultural. Or so it seems.

My original post, was asking whether anyone else had ever encountered anything similar and whether anyone knew of some reference material to this type of thing. At this point, all I have for documentation in the write up of the report for this site are two brief one-line mentions of this phenomenon. Given the fact there are now over 300 stone rings for this site and I am saying some of them are not real, I have to back that up. So far, I have not found anything in the literature, tho tomorrow I am speaking with a botanist about it.

Oh......I might add that this site has been previously recommended eligible to the NRHP as a TCP. NA consultation has determined the site to be culturally sensitive. In that regard I agree, especially given the numerous extremely large cairns thru-out the site. BUT...the stone rings are also considered culturally sensitive. What if some of them are natural and not cultural?

Hence the reason I would like some direction to some documentation of this sort of thing.


Post ID#8505 - replied 6/5/2008 12:13 AM


Thanks for the added information on the pictures and surroundings. It is hard to tell sometimes from photos.

I think I would include some data regarding the juniper trees rooting system, the ability to creep in and crack rock, lift it out of its way in order to anchor itself, freezing, the temperature tolerance of the trees and the rocks, the possible uplift of rocks due to ground freeze and thaw, and such. The data is there, it just has to be found. I found some stuff on Alaska and junipers roots, not specific to Wyoming, but to me it indicates that there has to be some information somewhere.

Anyway, my point is to document it, but present the possibility of natural processes at work in the area. It may explain what is happening and illuminate an additional dimension of why the area is important or sacred.

Sounds like a fun project. I miss Montana.

Post ID#8507 - replied 6/5/2008 7:59 AM


I'd like to offer an alternative to the formation of the rock rings (other than cultural or by juniper). BricksandSticks touches on the idea of cryoturbation which has been recorded as causing 'patterned ground' all over the world, often in periglacial climates or at least areas of severe freezing, which I am sure would apply in your case.

And the necessary presence of water to form the ice and move the rocks would also be an ideal source to promote tree growth. Search through some of the geology-based websites for the term 'patterned ground'. Here is a link to a brief discussion on the topic.

Pg 6-7

Post ID#8512 - replied 6/5/2008 10:36 AM



Thanks for the link. I will look into it and see where it leads me. The plot thickens........


Post ID#8513 - replied 6/5/2008 10:38 AM


yes, that is what I was getting at, just did not know the specifics, and it was a little fuzzy in my mind. thanks.

interesting stuff--can't open the article, but the abstract was informative and the other document was equally interesting.

Post ID#8599 - replied 6/7/2008 12:52 AM


Scott, you asked for something similar, ya we've got that in the deserts of SoCal. In the 20s Malcolm Rogers noted a bunch of "sleeping circles" in the desert gravels. He was of the opinion that they were of human agency. Others had speculated that they were the result of creosote bushes, which continue to grow out from the center as the original parent stock dies - kinda like redwood trees. The ever spreading ring of plants push the rocks and gravels out through generational growth and brushing action of wind acting on limbs that touch the ground.

Incidentally, the sleeping circles are usually man made as evidenced by other cultural materials in the area.

Post ID#8600 - replied 6/7/2008 12:55 AM


BTW, has anyone bisected one of these things, say down to 5 cm to see if there are stones below?

Post ID#8604 - replied 6/7/2008 11:44 AM


BTW, has anyone bisected one of these things, say down to 5 cm to see if there are stones below?

Are you talking about the stone circles in my post or the sleeping circles? As far as the stone rings in my posts, the answer is no. They have never been tested. At this point, that is not a part of the research design. I have thought about recommending something similar in my report to further investigate these things.

I worked once for a few months down in socal and encountered some of those sleeping circles. The ones I observed were previously recorded and all had cultural materials associated with them. They were quite interesting tho.

I have looked into the patterned ground angle and that is not what is going on on top of this ridge. However, I was surprised there are areas of patterned ground to be found out in my region. Who knew? You learn something everyday.

I am going to be returning to do some more work down around the ridge later this summer. There are a couple of areas I plan on visiting in my spare time that supposedly have this same thing going on with junipers in the center of stone rings. It intrigues the hell out of me and I am determined to figure it out.


Post ID#8610 - replied 6/7/2008 6:06 PM


[quote:="scottyj432"]Are you talking about the stone circles in my post or the sleeping circles?

Scott, I was speaking to your features, but you answered the question. I guess someone should look, dont you?

Post ID#9005 - replied 6/20/2008 5:27 PM


Hello all,
This is a great topic for discussion and thanks for the post. It sounds like a formation process consideration. I apologize for not pasting quotes or crediting statements. I add my thoughts as a sort of summary approach.

Here are the expanations I can think of.
1. Ring formation through "root push".
2. Ring formation by cryoturbation.
3. Ring formation by cultural action.
4. Ring "formation" by differential deposition/erosion of fines and organics.
5. Ring formation by combination, or cultural enhancement of natural arrangements.

There is also the possibility that any or all of these explanations may be responsible for the formation or apparant formation of entire rings or portions of rings. Statistics will probably have to be invoked to weigh the probability of each potential actor, but some solid research into the knowable natural processes that could contribute will be useful for at least getting a handle on that part of the equation.

Association of cultural materials may or may not be helpful since they may or may not have been deposited intentionally with the rings.

As has been sugested by others, collecting additional info through excavation adn sampling will help to at least define the inquiry. At the very least the area is of research value because of what we might learn about the formation process(es) of these things, cultural or not. With a better understanding of them and their formation it might alter the interpretation of other sites that include them, or perhaps draw attention to less obvious culturalf eatures previously attributed to natural processes. In other words we might realize there are far more cultural sites out there or perhaps far fewer than we thought.

Wow. What an indecisive load. I should have a PhD.

Post ID#9015 - replied 6/21/2008 12:04 AM


There are, indeed, a number of natural processes that can form a variety of rock alignments. Trees can, for instance, fall over, leaving depressions with rock and a berm on one side that can look very much like pithouses. Frost heaves can occur and animals can move rocks, too. However, from your pictures, scottyj, I think yours are probably cultural. When I first began finding sites on my own, in northern Arizona, one of the things I would do was look around junipers. Often, house sites had a juniper growing in the middle of them, most likely because of the different soil inside the house, enriched in the past with all sorts of organic material. The sites in your pix are very similar in appearance, though in a very different part of the country, climatically speaking. As Bob noted, artifacts are VERY helpful, but in my experience, high plains stone circle sites often have few or none, presumably due to the short-term occupancy of some of them. In any case, I think that the trees are there because of the circles, rather than the other way around. 8-)

Post ID#9017 - replied 6/21/2008 2:19 AM


[quote:="ROC"]Wow. What an indecisive load. I should have a PhD.

:lol: Sorry, you're over-qualified for that position....

Post ID#9062 - replied 6/22/2008 4:48 PM


It seems to me as Scalpcreek pointed out that they may be created by man considering that the centers do look void of any rocks. There is no way naturally that a tree root system, especially of a tree that small could literally push all the rocks out of the circle and create a close to perfect circle. I can understand them being natural if the circles were misshapen or there was a heavy-medium concentration of rocks in the middle. One more thing. Tree roots rareyl grow in circles and they are almost alway highly irregular in formation.

Now my question is, have any of these circles ever held artifacts or charcoal?

Post ID#9063 - replied 6/22/2008 4:55 PM


[quote:="Jeandron"]I'd like to offer an alternative to the formation of the rock rings (other than cultural or by juniper). BricksandSticks touches on the idea of cryoturbation which has been recorded as causing 'patterned ground' all over the world, often in periglacial climates or at least areas of severe freezing, which I am sure would apply in your case.

And the necessary presence of water to form the ice and move the rocks would also be an ideal source to promote tree growth. Search through some of the geology-based websites for the term 'patterned ground'. Here is a link to a brief discussion on the topic.

Pg 6-7

I would also recommend to look at the terrain to see if this theory is a liable one for this situation. What I mean is that the topography of the surface should support the idea of water being stored in the natural terrain at those points in order for it to freeze and form those circles.

The reality of the matter is that there can be various answers as to why these circles have formed. Just because a solution presents itself for one circle does not mean that the same solution pertains to all circles. This is why I think that each individual circle must be looked at separately.

Post ID#9066 - replied 6/22/2008 7:17 PM

Charlie Hatchett

Is there bedrock close to the surface? I wonder if the possible underlying bedrock has depressions, allowing fined grained sediment to accumulate whereas the areas outside of the depressions have very little topsoil?

Post ID#9071 - replied 6/22/2008 10:26 PM


First of all. let me apologize for not responding to the several posts on this topic since I last checked in here. I thought it had kind of "withered on the vine", so to speak, and faded away. Plus I have been out in the field and have not had the time to more further pursue things related to this discussion.

So to address some of the responses ( and I will not go thru the whole process of "quoting" and then posting, even tho I know that looks cool and all)....

Classarch has brought up some good points regarding the centers of these rings appearing to be devoid of rocks plus the idea/concept of water freezing and the resultant effects that may have had on the formation of the rings.

Yes, the centers of these rings around the Junipers are relatively devoid of rocks, at least the larger ones, but there are a lot of smaller rocks within the centers (that does not show up in the pixs). And these smaller rocks are typically of the size that were not used in a cultural way to make stone rings in the high plains. As far as the freezing angle.....I suppose it is a possibility, but at this point in time, I think it unlikely but I will certainly keep it in mind when I return to this area.

Another very good suggestion was provided by rkeyo: That the Junipers are there because of the stone rings and that in his experience such a phenomena was because (presumably) of the organically enriched soils associated with "house" locations. I am assuming rkeyo meant pithouse locations and that, I believe, has some validity as there have been several pithouse sites recorded and even excavated within a few miles of this site.

HOWEVER.......After reviewing briefly some of my posts and then reading Charlie's (a frequent and welcome poster to this site), I think I need to elaborate more on the more recent research I have done on the geologic processes at play here on this ridge.

Charlie had asked if bedrock was close the surface. That was in fact a very good question and one I should have addressed in this posting much earlier, so thanks Charlie for bringing up that very important "variable".

This site has (in general) very shallow soils (the exception are "saddles" between ridges/knolls, and the "Juniper-stone-rings" do not occur there). Bedrock outcroppings are common thru-out the site. These outcroppings are all sandstone. Overall, the soils thru-out the site range from 25 to 40 cm in depth.

This area was never glaciated. For an extensive period of time in the geologic past, the area was the "floor" of a huge inland sea; hence the sedimentary bedrock. During the various periods of glaciation in more recent times (geologically speaking), at least two and possibly three mountain ranges had developed extensive mountain glaciers that then suddenly melted and produced a huge "outwash" of metamorphic glacial rocks that were deposited over a wide area.

Then, in much more recent times (geologically speaking), a seismic fault developed along the north side of this site and as a result, the ridge on which which this site is located, was thrust upwards at least 500-600 ft. Since then, because of the thrust angle of the ridge, severe erosion has taken place; approximately 250 ft of surficial deposition from the glacial outwash is now gone. As a result, sedimentary bedrock has been exposed plus the larger glacially-outwashed rocks have been concentrated across the rather shallow soils of the ridge on which this site is located. For this reason, I do not believe "patterned-ground" is a plausible explanation.

I should also add that these "Juniper stone rings" are not perfectly circular, at least based on the interior diameters. BUT...., this is also true of most of the stone rings we recorded that appeared to be cultural; that is not unusual, at least in my experience and I have recorded hundreds of stone rings on the high plains in my career.

I am clueless as to the root system of a Juniper tree. First of all, there are several types and second, depending on the subspecies, they can live to varying ages. Then, depending on the climate, if the tree were to die, fall over, etc., some subspecies' trunks can take a hundred years or more to decay completely away. This site is located in an area that at least three subspecies of Junipers "converge". All three have different unique stats. That much I know. intended meeting with the "botanist" never happened as she was called out of the office on another matter. Hopefully, I can meet with her tomorrow.

I think the whole thing is natural (and have from the start) but several responses to this topic have forced me to examine other explanations. And I have yet to fully "disprove" those explanations, at least in my mind. The pithouse/organic soils concept is perhaps the most intriguing and possibly the most culturally explainable.

I might add that testing of these possible "Juniper tree rings" is rather unlikely at any time in the future. This site is considered a Traditional Cultural Property by several Native American tribal groups who generally oppose archaeological sub-surface "intrusions" of features/sites. So that is a factor as well and one that must be respected.

I appreciate all the input from one and all.

Keep the questions flowing.....


Post ID#9086 - replied 6/23/2008 2:02 PM

Charlie Hatchett

Nice summary of the geology. Without being able to dig a portion of the site, it may be hard to ever know for sure what's going on with the contrast between the finer grained sediment surrounding the junipers and the coarse sediments/ rocks out side the area of the junipers. My father has a ranch just outside of Austin that has a lot of junipers. Next time I'm out there I'll have to take a close looksey. When I first saw your pictures I thought of dad's place: thin topsoil with junipers on the uplands.

Post ID#9094 - replied 6/23/2008 3:26 PM


I just thought of something else. Is there a possibility that Native Americans created the rings and then planted the Junipers within them for cultivation? I have seen many cases in Greece due to the dryness of the climate in which rings were created in order to help it accumulate water in places where water fall is not high. In Greece, as well, the surface soil is extremely thin and lacking.

There is a long list of uses for the berries and the oils. It is common place in Native cultures to use the plants available to them for curing ailments so why not the Juniper. Cultivation has been around for quite some time in North America so why not the cultivation of the Juniper?

Here are a few from the following site.


4 oz - Juniper /Juniperus communus Juniper Berry: (Juniperus communis) Eastern Europe Juniperberry - Steam distilled from the berries or a combination of berries and twigs. Scent: Balsamic, spicy, similar to pine. The scent is sweet and balsamic (similar to Gin) and the oil has antiseptic qualities.

Description: The oil is distilled from the berries of this shrub. Oil from the ripe fruit is superior to that of the liquid distilled from the unripe, green berries. The berries take two or three years to ripen, turning blue when ripe. Juniper oil is often adulterated with turpentine, which diminishes its quality. The oil is either colorless or pale greenish-yellow.

Traditional uses: to energize and relieve exhaustion, ease inflammation and spasms, for improving mental clarity and memory, purifying the body, to lessen fluid retention, for disinfecting. It is often prescribed by herbalist for its antiseptic, disinfectant, sedative, and stimulant properties. It may also be blended with bergamot, grapefruit, lavender, lime, and rosemary to prepare many different mixtures for different ailments.

Uses: The oil is used as a diuretic and carminative for flatulence and indigestion. It also aids in relief of stomach complaints. A few drops in a bath may relieve premenstrual bloating. The oil can also be applied externally as a stimulant. For aching joints, juniper oil may be mixed with a carrier oil and rubbed onto the body. May cause irritation of sensitive skin. Should be avoided by those with kidney disease.

Qualities: Anti-rheumatic, antiseptic, diuretic, stomachic, carminative. Antiseptic, cleansing, promotes mental clarity, stimulates lymphatic drainage.

I'm thinking the reason there is no cultural material present is due to the cultivation. So I suppose the question is has there ever been a study on the cultivation of the Juniper?

Post ID#9097 - replied 6/23/2008 8:36 PM



I'm not degreed in any of these fields, but, to me that is the most common sense explanation yet.


Post ID#9108 - replied 6/23/2008 11:33 PM

Charlie Hatchett

Is there a possibility that Native Americans created the rings and then planted the Junipers within them for cultivation?

They grow abundantly, today, in Texas with no human involvement. Not sure about Wyoming. :?

Many ranchers in Texas thin them out because they so densely populate the land. Same with Mesquite.

Post ID#9115 - replied 6/24/2008 10:35 AM


Charlie makes a good point. The junipers in this part of Wyoming also grow abundantly, so "cultivating" them seems unlikely. However, as Classarch pointed out, they did and do have many uses in Native American culture. The leaves, berries, roots and cones were all used for a variety of medicinal treatments. The berries were used for food. The stems of the junipers were used for bows and the boughs were used in purification rituals and to drive away evil spirits.

I might add that the Botanist was of no help.


Post ID#9120 - replied 6/24/2008 12:04 PM


very interesting topic, sorry I did not see it earlier.

There have been some very good ideas proposed, so here is just one more to throw into the "ring"

Assuming that the rings are cultural (purpose to still be determined) the question is "Why are Junipers in so many"? Beign from the east Junipers are not a large part of our botancial focus (though they are present) - but I did see in one post a mention of the berries. Have you considered the possibility that whatever function the circles served, inlcuded the use of juniper berries - which may have resulted in seeds ending up in or near the circles more often than they are randomly dispersed? just something to think about.

As for are the rings natural or cultural - check with the tree folks, is this something typical for Junipers to do? they may already have your answer.

Post ID#10992 - replied 9/12/2008 5:50 PM


It has been awhile since I revisited this thread and thought I would add an update to what I have finally concluded about this unusual phenomenon.

I have spoken with a variety of plant and tree experts and none of them had ever seen anything like this...junipers within stone rings. I explored the cultural angle as well as the root push angle and finally ruled them both out as plausible explanations.

The cultural angle as suggested to me by several colleagues involved the idea the rings had central hearth features and juniper seedlings eventually became established within the organically rich soils of the hearth. In a nutshell, what I found is that juniper seedlings generally are established beneath the canopy of sagebrush and that it takes over 30 years before a juniper has developed enough of a root mass to fully support itself with nutrients and water. The canopy of a sagebrush aids in biomass nutrients and assists with soil moisture absorption. Therefore, the most likely scenerio for a juniper to have established within a hearth feature would almost certainly have been preceded first by the establishment of a sagebrush that would then have to have matured enough to provide adequate canopy cover for the juniper seedling. The fact that several of these stone rings have junipers in them and that all of them had hearth features and then had sagebrush growing in the hearths before the juniper seedlings established is somewhat unlikely I think.

The root push idea did not work out either. I found out that the lateral root system of a juniper radiates out from the tree trunk by a distance equal to at least the height of the tree and sometimes 2 or 3 times the height of the tree. These rings are all 5-6 meters in diameter and the trees are all 5-6 meters high. Therefore, the lateral root systems radiate out some 2-3 meters beyond the stone ring walls. It would seem that if the rocks were root pushed, they should have been pushed out to at least the end of the lateral root system and they apparently are not.

That then led me to reconsider Jeandron's idea of patterned ground. After doing some indepth research into it, I came to the conclusion the formation process involved with patterned ground held the answer.

The basic idea behind patterned ground formation is that thru cyclic freezing and thawing of soil moisture, the finer grained sediments and rocks are "sorted"--soil tends to sort to soil and rocks sort to other rocks. Eventually, the relatively rock free soil areas accumulate more moisture than the more rocky areas. Because water when it freezes increases in volume by 10%, the soil areas expand against the less resistant and drier rocky areas and pushes the rocks away from the soil areas, The repeated freezing and pushing creates geometric shapes in the landscape like polygons and circles.

What I think formed these stone rings is a similar process, but on a smaller scale. Beneath the canopy of the juniper, a layer of litter accumulates (duff) [I returned to this area and looked again and yes there is duff beneath the canopy despite my earlier saying there was not]. This litter helps to retain soil moisture and the canopy reduces soil evaporation. The area surrounding the juniper/stone rings is open cover and therefore retains less moisture and experiences more soil evaporation and is therefore drier.

So, when the ground freezes, the area beneath the canopy expands and the rocks in the soil are subjected to frost heave and lateral push by the frozen soil. Eventually, just like with the formation of patterned ground, the rocks are sorted away from the tree trunk and towards the open cover surrounding area that has less moisture in the soils and is the path of less resistance for the frozen water in the soils beneath the canopy.

However, the lateral pushing of the rocks ends at the drip line of the canopy as this is where the soils of higher moisture ends. This then results in the ring rocks being locating along the drip line of the canopy. This is why the diameters of all of these stone rings is nearly identical to the diameters of the juniper tree canopies and also why there are no large gravels or rocks beneath the canopies.

Anyway, I had to return to this area for another project and took some time after work one day to go back and look at these rings again. I scraped away the litter beneath the canopy of some of the rings and I could not find any large gravels or any rocks. I measured the canopies too (I also learned that the diameter of a juniper canopy is nearly a 1:1 relationship to the height of the tree--who knew).

So after a lot of research, I think this is the most plausible explanation.


Post ID#11019 - replied 9/15/2008 2:29 PM


Cool info Scott. I especially like your summation statement:

[quote:="scottyj432"]In a nutshell, what I found is

Would that be a Juniper nutshell?


Post ID#11053 - replied 9/17/2008 2:16 PM


:lol: Dave, I know, that's why as a joke it's funny.



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