One of many
trip reports under the
SilGro home page for Alan Silverstein and Cathie
Grow.
Email me at
ajs@frii.com.
Last update: March 29, 2024
(Previous trip report: 2010_0808-15_LakePowell.htm)
With an appended followup section about our return to Black Mountain, August 20-21; and later postscripts too, with important errata.
(Note: Thumbnails here are hyperlinks to bigger images. Expand new windows to full size to see biggest views.)
A friend and I went looking for the oldest living tree in the Rocky Mountains. It had been growing for over 2500 years on Black Mountain (11654') in south-central Colorado about 36 miles SSW of Pikes Peak. Since we didn't know exactly where the tree was, finding it entailed quite an adventure! This was both in terms of detective work and physically roaming around the steep, loose, overgrown south side of the mountain hunting for the tree.
This essay began as a brief summary of many odd connections that led us to the tree. But a much longer recounting was required to do the story justice. I hope you'll enjoy coming along for the ride.
(And dear reader, if you were in a group that lost a digital camera on the mountain -- email me! See the end of the first section of this report. [But wait, later I returned the camera to its owner!])
Note: I misnamed this file "OldestTreesInColorado", but realize now they're actually the oldest in the Rocky Mountains!
Disclaimer: If you expect me to tell you exactly how to visit these trees for yourself -- I'm sorry but I can't do that. We don't want to make it too easy for too many people to go there and trample on the fragile hillside. I want to share the story for your entertainment, but the trip itself should remain only for the highly motivated few who are willing to do detective work (as well as legwork) like we did.
This webpage does gather in one location some information that is (mostly) otherwise publicly available, and I hope I never regret doing that. Unfortunately it's impossible to hike around on this hill without at least knocking a lot of rocks out of place. If you go there, please do your best to tread lightly -- especially missing the rare baby bristlecone pines that are tomorrow's next generation.
Background: Years ago I learned about ancient bristlecone pine trees (Pinus longaeva) growing in California and Nevada. I hiked among them in the Ancient Bristlecone Pine Forest in the White Mountains of California looking for "Methuselah", the oldest living tree known today. I read the story of how the very oldest known tree, "Prometheus", age > 4800 years, was "accidentally" cut down in 1964 on Wheeler Peak, Nevada. When I toured Great Basin National Park and inquired about that story, I discovered that the slab I was touching in the visitor center was from that very tree.
Later I also heard that creosote bushes, growing outwards in rings, can be much older than any bristlecone. Also aspen groves and possibly other "clonal" organisms, can be much, much older. But they lack the appealing style and grace of ancient pine trees.
When hiking all over Colorado for many years, I knew we had some bristlecone pines (Pinus aristata) in the "mere" 1500-year-old range. Once I even explored a grove on the south ridge of Mount Princeton. But I never bothered touring the oldest known cluster on Mount Goliath near Mount Blue Sky (formerly Evans).
I did not know about a 1992 academic paper reporting a 2500 year old tree in Colorado!
Cut to the present [which was 2011 when I wrote that], let's count the connections...
Major King was the Channel 7 (Denver) northern bureau photojournalist and a fellow avid rockhound. He got interested in this topic several years earlier. He bought a T-shirt at the USFS office in Fairplay showing a tree alleged to be 2435 years old (connection #1). Also he somehow came by three digital photos (printed copies only) of two of the trees, with no additional information (connection #2).
In June my wife Cathie Grow and I invited the King family to join us (their first time) for a night at her cabin in South Park. Major talked about wanting to find and film the trees on Black Mountain, about a hour beyond (south of) her cabin (connection #3). We ended up making a long, rough drive with two cars completely around the mountain counterclockwise one Saturday before going back to her cabin for the night. Along the way we stopped into the USFS office in Fairplay, but they wouldn't or couldn't provide us any more information about the old trees.
So then I got fired up too. I found online the first page (only) of a four-page research article from 1992 by Craig Brunstein and David Yamaguchi (connection #4) that said in part: "...exceeds the age of the oldest previously reported Rocky Mountain bristlecone pine by 846 yr". I couldn't figure out how to view the remaining three pages, nor even buy a copy (the website didn't work right). Anyway the first page alone was a goldmine of information that narrowed down the area to search closely enough that I wanted to go do it.
Noting that Craig was from the USGS in Denver, I emailed to Pete Modreski who worked there. Pete said he used to know Craig, but he died in 2008 at the age of 56. Craig apparently studied the trees as a hobby with some funding support. When he published this article it must have made quite a stir because he trumped the oldest previously known trees in the Rocky Mountains by a wide margin.
Pete pulled a copy of the entire article via USGS access without even discovering there were public access restrictions, and he printed a copy for himself. He also told me about a USGS poster that Craig had a hand in creating, about the oldest trees, and pointed me to a website where we could view it but not read most of the text. [Aug 2021: The link no longer works, you'll have to hunt around to see if you can still find the poster on the web somewhere.]
Major and I decided to go tree-hunting (not rock-hunting for a change) the second weekend of July. His son Logan King demurred, his wife Nancy King, and Cathie, didn't want to go to Cathie's cabin so they stayed home, nor did my friend Jenny Pruett want to visit the cabin with Cathie on her way back from Fort Collins to New Mexico! Hence it was just Major and me out adventuring in my Subaru wagon. The weather forecast was for a high chance of monsoonal thunderstorms, but we seized the weekend and went anyway.
Pete was kind enough to offer us copies of the USGS poster. So on the way through Wheat Ridge we stopped by his house, picked up the posters (connection #5), and also took a tour of much of his rock and mineral collection. We discovered he had printed the entire article, and he let me take that with us (connection #6), which was invaluable! Plus he gave us copies of the USGS topo map showing Black Mountain! Which also turned out to be pivotal (connection #7).
With the article and posters in hand, combined with Major's prints and T-shirt, we determined that the tree depicted on the shirt was the fourth-oldest known (about 2220 years now), not the oldest (now over 2500 estimated total years of age). Furthermore it was an inaccurate artist's depiction that excluded surrounding trees! However it did reflect the shape of the tree's dead branches.
We also knew now, based on the poster and a later page of the article, that the printed photos in hand were of the oldest and fourth-oldest trees, although not where the specimens were on the mountain. We knew from the article that they were on south to southeast slopes between about 10760' and 11250' elevation, a large area of difficult terrain to explore on foot.
Before leaving home I printed a copy of a Google map showing a road up to the edge of Pike National Forest land on the east side of Black Mountain. But the Google view didn't show a 4WD road on the southeast side, which is normal, they don't usually include them. And the USGS map didn't show the other road either! Maybe too new?
During the drive down the weather looked ominous. I was pretty sure we were going to end up passing time in the car waiting for a thunderstorm to abate. But Major was mostly right, the old trees are there because they grow in a rain shadow, an unusually dry area. When we got near Black Mountain it was relatively clear and pretty, although the southeast slopes were disappearing into shadow for the evening.
We thought we'd have to drive in and hike up to the grove a mile or more from the east. As it turned out that would have been really awful. Before exploring up that well-marked side road, we drove south several miles instead to the 4WD road junction. I didn't expect much because a USGS map saying "4WD" usually means seriously rough or steep terrain. To my surprise my Subaru wagon got all the way up the road with some care (and a hot motor!), 2.3 miles northwest one way to a junction at about 10320'.
From the junction we drove less than half a mile, and several more hundred feet steeply uphill, northeast on the right-hand two-tracker. Another vehicle was precariously parked near the end! I tried to drive a little higher beyond, scared myself, and cautiously backed down to where they'd stopped. "No worse than San Francisco streets, right?" I kept reassuring myself.
Major grabbed his gear, including a heavy video camera and tripod, intercepted the other party, and interviewed them as material for a video to-be-produced about the entire experience. Meanwhile deciding on discretion over valor, I turned the car around gingerly and drove downhill to park on a slightly less tippy bit of terrain nearly down at the main junction near an old mine site. Then I bushwhacked steeply uphill through an aspen thicket (interspersed with pine trees) to meet up with them.
(We brought backpacks with us, but decided not to try sleeping up high on the steep, rough hillside. Also it would have taken precious time to load them up.)
Major and I spent a total of about two hours (Saturday evening) and again six hours (Sunday morning and afternoon) scrambling around the steep, loose terrain of the south side of Black Mountain looking for the oldest trees. We hunted all over without success Saturday evening before coming down in twilight.
Well "success" is a relative term! It was beautiful up in the open forest, with lots of ancient, gnarled, twisted old wood, but also very tough and wearying clambering around cautiously on steep, loose terrain. It was harder for Major since he carried the heavy camera and tripod. We saw the mountain's shadow rising. A small storm blew past to the south of us producing a series of gorgeous partial rainbows. Clouds swirled around the top of Pikes Peak in the far distance.
It became clear to both of us how hard it was going to be to find any of the four trees known to be over 2000 years old (according to the 1992 article). We only had pictures of two of them -- Major's T-shirt fortunately not the only representation of the fourth-oldest. But Major did locate a tree bearing a small metal disk with a number, "CB-2", and later "CB-25" also. "CB" was obviously Craig Brunstein, but his journal article referred to the trees with years, such as both "CB-90-1" (which we later confirmed to be tagged "CB-24") and "CB-91-1". Lacking the secret decoder ring, we couldn't correlate Majors' finds with the list.
(Footnote: Later I got ahold of Craig's co-author, who didn't have the cross-reference either, and didn't know where it might be. It was also not on file with the USGS. Sadly it might be lost already to the sands of time.)
Major brought family radios but the batteries didn't work very well... We got separated. Wandering around the mountainside watching the time until sunset, I decided I finally had to head down no matter what. Eventually by yelling loudly and getting a response, I could tell Major was below me, and proceeded directly his way.
He reached the car before me. Then we drove downhill looking for a flat spot to camp. We found a decent location about 600' downhill, set up my tent, had dinner, enjoying a thunderstorm lightshow, sat out a little rain in the car, and went to bed about 11 pm. I was happy to have the tent (and rainfly) because it got wet again at some point overnight.
Major wanted to film the oldest tree at sunrise. That would have meant getting up about 4 am. But we were exhausted and didn't know where that particular tree was, so we didn't exit the tent until about 6:30, an hour after sunrise. It was surprisingly cloudy anyway, not great morning light.
We broke camp and drove back up the hill to start hiking again at about 8 am. Down below we debated where to park for the day -- left, right, or immediately at the junction. I thought we should pick up where we left off, heading across the mountain [details deleted, sorry]. That certainly meant the least bushwhacking. But ultimately Major was proven correct, if we'd started further [deleted] we might have found the oldest tree sooner.
Anyway after we parked, Major went ahead of me and missed the lowest talus slope, while I managed to break out of the bushwhacking (and start rock scrambling instead) about as low as was possible. We kept in touch by radio and eventually met up about 500' higher on the hill. I looked all around. There was no sign of either tree that we'd recognize, just a lot of "false" leads to check out.
I took a break high on the hillside near where Major had parked his pack and video gear. I enjoyed exploring and photographing some beautiful ice-sculpted, orange-stained logs lying all around. It occurred to me that hunting for the oldest living tree meant less attention to deadwood that might be four times older!
I rested and snacked there much higher than the car at about 10 am studying my GPS coordinates, the map, the photos, and the article. I memorized the four characteristics of a very old tree: Large diameter, sculpted wood, dead crown, and strip bark. It was clear to me that any very-oldest tree must be nearly dead, otherwise there would be even older ones closer to their demise.
I didn't realize that nearly-dead and eroded implied the tree would necessarily be short and squat, thus hard to find. It was hard to tell the barely-alive trees from the totally dead ones anyway since the green branches all merged together from most angles. There were a lot of dead trees still standing monumentally on the mountain, and I couldn't distinguish at a glance one type from the other.
Then finally I noticed that Major's picture of the fourth-oldest tree showed [deleted, sorry, you'll have to figure this out for yourself!]
I told Major by radio that I hadn't found the #4 tree yet, but I'd just figured out how to do it, and it didn't appear to be very far away from me either. I made my way slowly and carefully down the loose, bouldery hillside trying to [find the tree using all available information]. It appeared I only had to go a little ways down and to the left.
I thought: No way can this be right, I was here last night (I think, it was hard to be sure on that hillside), and again this morning (I think). Well dang, it should be right below me! But I don't see it.
Now Major had observed there were some [identifying features] on the tree in the picture. I looked down the hill again about a hundred feet and... There's the tree! Nestled against taller bristlecones only 200 years old (I found out later), so you couldn't even see the live branch on this one to tell it was not fully dead. It was only about 12' tall, very easy to miss. The original main trunk ("pith spike") was nearly completely eroded away.
Cool, I thought, we're not going home empty-handed! I told Major by radio that I'd found the #4 tree just a hundred yards below his pack, and gave him a yell to indicate where I was. Then I made my way down to the tree to study it closely.
I wanted to recreate the photo in my hands -- which I did later, but it was difficult, requiring positioning within inches. Lining up the shot, I looked at the ground uphill from the tree and saw... A digital camera, lying right there where someone had left it! (Connection #8.) Not in terrible shape, but clearly it had been there through at least one rainstorm, and it wouldn't turn on. I wish now I'd thought to swap in new batteries immediately. Instead I took the camera home with me to study later... More on that below.
I spent about 90 minutes studying (carefully and respectfully), photographing, and hanging out on a pleasant, partly-cloudy summer morning in the vicinity of this "merely" fourth-oldest, but very beautiful close-up, tree in the entire Rocky Mountains. The wood was carved by nature, moss grew on parts of it, and a few small cones appeared on the one live branch.
A little metal tag nailed to the backside of the tree said "CB-24", but I knew from the picture that it had to be the "CB-90-1" tree listed in the journal article. Thus: 94 cm long axis, 66 cm short axis, oldest dated ring from 191 BC, estimated age 2200 years in 1992. I also found three increment-borer holes near the tag where the samples had been taken 20 years ago for ring dating.
Eventually Major arrived, dropped his gear, and wandered off again looking for the oldest tree while talking with Nancy on his cellphone. After he finally got back, I headed up to the top of Black Mountain! Of course I watched all along the way for the oldest tree, but not seeing it in particular among many other old, twisted specimens.
It took me over half an hour, huffing and sweating, to gain about 500' more through a steep, overgrown thicket to the flattish, tree-covered summit ridge, then east and up to the top through a mixed forest. Here just after noon I found an excellent view northwest around to southwest above a cliff, at a flagpole bearing a large, shredded US flag. (Pikes Peak also appears in the nearby photo.) There was a summit register tube, and a big old chunk of bristlecone wood inscribed with a few autographs going back to 1966.
I rested and ate lunch up there for 35 minutes before starting down again. Major said by radio that he kept exploring the hillsides below, but was getting tired of traversing the difficult terrain. I intended to swing further west, then diagonal down and back while hunting. However I crossed my own path and found myself not far off where I'd started up to the top.
Early thunderstorms threatened from the west, and Major headed down the hill. I took my time meandering down, watching the weather, as one small storm blew past us with only a few distant thunderclaps. A few times I even climbed back up a hundred feet or so to check out another ancient tree, but never found "the oldest". Magnificent weathered bristlecones were everywhere on this complex jumble of open rocky hillsides and dense thickets.
Eventually as I got way down the hill I abandoned the search. Plus another more ominous storm approached. I bushwhacked down to the car just in time to unload before it started raining. So at about 2:40 pm we drove a long way down the hill. When we got to a place and time without rain, I cleaned up and changed clothes for the rest of the trip.
Major was agreeable to going home the scenic route. We enjoyed a pretty drive from Guffy to Florissant to Woodland Park and down to Colorado Springs, chasing and only barely catching part of a now monstrous thunderstorm that didn't do much to wash the road dust off my car. We stopped at the Pikes Peak Rock Shop, then a KFC in the Springs, then "enjoyed" over half an hour total of delay in stop-and-go traffic for miles heading north out of town... Sigh. We didn't make it home until about 8:30 pm.
Hey wait, wasn't this supposed to be a story about visiting the oldest tree in the Rocky Mountains? Well now that's the rest of the story.
That evening Cathie and I cleaned up some corrosion in the digital camera I'd found, I put in new batteries, and behold -- it woke up! Immediately I saw there was no SD card, but 24 images in memory, and the little screen clearly showed -- to my astonishment -- the memorized shape of the oldest tree we'd been hunting! (That's it tucked against the other trees in the picture nearby. I have no idea who the climber was.)
We had other photos of the oldest known tree, but none this useful.
I eagerly tried to download the camera's memory, and it worked! It was full, with gaps in the file numbers like someone had deleted a few pictures to make room. The photo dates were all 1/1/2000, no useful info there, although at some time in the past the clock had been set and some folders were stamped 2009.
The snapshots showed a moderately large group of people toiling up the hillside to visit both the oldest and fourth-oldest trees. They must have known where they were going! I thought: I'd like to know how. Maybe I'll be able to talk with them, and return the camera to them... We'll see. There was no ID on the camera, but an early picture showed a truck parked on the hill -- with the license plate visible!
The Fort Collins Police Department Records division couldn't tell me who owned the truck, but they tried calling the owner for me... And the phone number on file had been disconnected. But they offered to mail a letter for me to the address of record! Now we waited, and hoped for a response...
July 26: No luck! The truck's owner apparently moved and changed their phone number without telling the DMV. The letter sent by the FCPD came back undeliverable. Well maybe one of the people in their group (I counted at least six different individuals in various photos) would Google their way to this report and email me? [2023: Never happened.]
Meanwhile some of the pictures of the oldest tree included some [clues] that would allow us to hike directly to find it. I'd already used Google Earth to get a pretty good idea where it must be, further [direction] than we had time to explore. Major and I hoped to return later that summer with anyone we could drag along with us, to find the oldest tree, and also get him more footage for his video.
Followup, August 20-21, 2011:
We had quite an adventurous return to the mountain on the weekend of August 20-21. We found/visited six of Craig Brunstein's tagged trees (CB-1, 2, 18, 23, 24, 25), including finding the oldest known living tree in the Rocky Mountains (CB-18), and two others we hadn't noticed before.
On Friday evening after work, my wife Cathie Grow and I drove to her mountain cabin that was about an hour north of Black Mountain. Arriving well after dark, we were met by friend Jenny Pruett from New Mexico, who spent two nights at the cabin with my wife. On Saturday morning we all drove down to Jefferson at about 9:30 am to meet the rest of the crew (five other people in three other vehicles). Cathie took my car back up the hill, Jenny drove all the way to the mountain and back just to see it (hauling firewood from the cabin for us), I rode with the Kings, and Rich left his car in Jefferson to ride with Mike and Phyllis.
Confused yet? This was just the beginning of an intricately woven flow of events!
Anyway the caravan turned off the pavement on Park County Road 88 near Guffey, where we picked up David Mason, the Colorado Poet Laureate, with his car. About nine miles later we turned up the 4WD road mentioned earlier in this report.
Eventually we had three vehicles and seven people remaining at the junction below lower timberline at about 10300'. The firewood went up the last part of the hill in David's car -- its third trunk of the day!
The weather was partly cloudy and occasionally threatening, but it stayed good for us until after sunset. Six of us bushwhacked up the hill a bit before 1 pm, and made our way fairly directly to the oldest known living tree in the Rocky Mountains (CB-18). It was about 200' higher than my best guess.
Up close and personal, the ancient tree was much more beautiful and interesting than I expected from the pictures.
We hung out here a long time. David even penned a bit of verse on the spot and read it aloud for Major's video. Here it is, posted with his permission:
BRISTLECONE PINE
We've always known how we are like the trees and not like them.
We walk and live more briefly.
Two thousand years of nights under the stars, eclipses, lightning, most
of it without a whisper from the noisy biped creatures who have come
here now with hopes and cameras, notebooks, measuring tapes.
What was it like when fire filled the high valley, when bull elk bugled
mating calls to vast grazing herds, when the first satellite deranged
the heavens?
If wind were wood it might resemble this fragility and strength, old
bark bleeding amber.
Its living parts grow on away from the dead as we do in our lesser
lives.
Endurance, yes, but also a scarred and twisted beauty we know the way we
know our own carved hearts.
After a while at the 2500-year-old tree, some of the group headed downhill while the rest of us proceeded onwards. We came across a spot where persons unknown had long ago chainsawed slabs out of many dead and down trees, presumably for dating purposes.
We also relocated CB-25 higher on the hill, a tree Major had found the previous month, and admired it.
This time I came armed with a tape measure and a copy of Craig's "table 1" sorted by long diameters in inches. We took various measurements of each tagged tree and tried to match it to his list. The known #1 and #4 trees fit the data beautifully, but with CB-25 it was hard to know where to take the measurement. We got values ranging 41-45", so we don't know if it was CB-90-10 (#2 tree, 48", age 2450-2500 years) or CB-91-6 (#10 tree, 39"). However it was the only one we saw with serious heart rot matching the table, so we think it must have been the #2 tree even though it looked pretty healthy for its age! Lots of living bark anyway.
We continued over to visit the #4 tree again, CB-24. There were no more digital cameras lying on the ground (grin). We bemoaned our failure to think ahead and bring a cheap one to leave as an offering for the next party!
Eventually we headed downhill. The ladies having already driven two of the vehicles further down to an aspen grove and set up camp, the rest of us caught a ride with David, although Major walked -- still carrying his heavy camera.
Pete Modreski (USGS) arrived in camp from Colorado Springs before we got there. The more the merrier! Meanwhile David took off to head home before dark.
Down at camp I was pretty tired, but got my tent and rainfly up before dinner and dark. Also prepared to build a campfire, but first had to eat in the tent during twilight while it rained hard. The precipitation stopped long enough to get a nice fire going, then several of us huddled around it as it rained off and on again for several hours. So much for being in a really dry part of Colorado!
Sunday, August 21:
After a decent and dry night's sleep I awoke shortly after sunrise to see others already taking pictures of the very pretty clouds over the mountain. We had breakfast, Rich and I moved our gear from two other vehicles into Pete's, some people stayed at camp, Major walked up the hill, and Rich and I rode up with Pete for the morning.
Pete hadn't been to the trees before, so I took him on much the same route as yesterday, with additions, and Rich tagging along too. Major returned to the #1 tree again for more filming, then headed down.
In the photo nearby you can see a burl on the tree, and looking closely below and to the right of it, one of Craig's increment borer holes -- possibly the very sample that dated the oldest ring in this tree to 442 BC!
Today going further uphill, the three of us (re)discovered CB-2! This was the other tree Major had found the previous month.
Despite measuring it, we weren't sure which tree it was. It might have been the #10 tree, in which case CB-25 was #2, or maybe one or more of these trees weren't even in Craig's table. Anyway it was fun to find. Furthermore, the GPS said it was less than [small distance] from the #1 tree... Meaning Major had very nearly found that one in July before I called him back to join me at the #4 tree! Another odd (dis)connection.
We headed northeast toward the #4 tree. Passing the uphill point to hike to the summit of Black Mountain, Pete and Rich said, "Why not?" and so all three of us toiled up to that point. It was a long, tough scramble north to the ridgeline again, then a moderate walk east through trees to the high point, taking most of an hour. By now there were some mildly concerning clouds building up, but again today we had no real weather issues.
Naturally on the way to the top, eagle-eyes Rich spotted another tagged tree (CB-1) that I hadn't noticed a month earlier, right along our route... Amazing. It was higher than I expected any of Craig's tagged trees to be, and was right near a cliff edge.
After a pleasant time on the summit and sidetrip to look north, then a long, tedious descent, we wandered over toward the #4 tree again. When we got close I said to Pete, "there it is, she's all yours." A bit later I saw him photographing a different dead-looking tree about 30' up the hill. I said, "That's not it, it's lower down." To which he replied, "But this one has a tag too!"
Son-of-a-gun it sure did, "CB-23". How had we missed that during two previous visits to the area? Well the tag was on a side of the "slab trunk" that was rather uphill and hidden, that's all I can guess. Which tree was it? Dunno, maybe #7 or #8 if it was on Craig's list. Our measurement was ambiguous again.
Well now we were all about tuckered and tree'd out, after unexpectedly visiting six tagged trees in one day. So we headed down the hill uneventfully and back to Pete's car by about 3 pm.
Much much later, we dropped Rich in Jefferson to head home, then Pete took me up the hill to Cathie's cabin, now about 5:30 pm. By the time Cathie and I finished cleaning and packing, we didn't start for home ourselves until 6:45, and with a nice dinner break in Denver it was after 10 pm before we started unloading in the garage. What a weekend!
Postscripts:
August 6, 2021: Due to this webpage, about a year ago I received two emails within a month from two people, Than Ball (email) and Ben Loftin (email), both of whom were interested in this topic. We talked a lot since then, I provided them more information, and both have visited the ancient trees on Black Mountain.
These guys determined that what we thought was the oldest tree, CB-18 (aka CB-90-11 in other contexts), was in fact not the oldest one. I saved a lot of emails and pictures from them that I still haven't dived in to process! (It's laborious.) So just beware that some of what I wrote above isn't accurate. Eventually I'll parse, digest, and revise this report and some other, non-published, files.
Meanwhile Than summarized this way: "CB-18 is the second oldest tree, CB-90-10. And CB-23 is now known to be CB-90-4 (a ~1884 year old tree in 2021)."
To arrive at this conclusion they used a gorgeous, detailed USGS publication that apparently I learned about, and came to own in print, from 2006: Growth-Form Characteristics of Ancient Rocky Mountain Bristlecone Pines (Pinus aristata), Colorado by Craig Brunstein. But I/we didn't know about this publication until after we were done with our own explorations and I wrote this report!
One of these guys also pointed me to a really nice, although long, article in the New Yorker magazine from Jan 2020: The Past and the Future of the Earth's Oldest Trees.
(Next trip report: 2011_1130-1217_PanamaCanalCruise.htm)