Diameter was measured several times at several heights for several purposes. The girth points are from dbh diameter known as diameter at breast height. There is about 10 feet difference between high and low sides. The difference was averaged between high and low sides in the strictest sense for where the trunk visibly meets the earth, then splitting the difference. The nationally recognized formula for points adds height + girth + 1/4 crown. I used Chris Atkins' height measurement. Average diameter at dbh is 27.38 ft.
Grogan's Spring - September 2016 was a dry summer virtually no rain June - September. It was a surprise to approach early autumn and feel boots sink ankle-deep into saturated earth - Grogan's Spring revealed. That answered how this redwood and a few more in Olympian Grove attained their size. This is similar to the spots near Orion and Episkopos in Redwood National Park. Grogan's Spring further debunks a super DNA hypothesis. For example, Archangel is a group cloning tissue from large redwoods, and seem to propose that largest coast redwoods have superior DNA. Contrary, I teach that largest coast redwoods happened to be in better conditions and dodged the bullet when nature threw catastrophes their way.
Other Notes: I dropped the menu rank for Grogan's Fault to #2 largest and formed a new page The Emissary to represent the #1 arena for any others not yet undiscovered, or unpublished. Many measurements were done by men of the "redwood network". In 2016, Redwood Ed, who hadn't seen this redwood, divulged a measurement based on a subjective imaginary line which "sliced-off" some trunk girth. The diameter above is the entire trunk. Each measure had a reason and purpose. The 27.38' girth uses a measurement devoid of any man-made shape alterations. Following the first diameter measurements, more lower trunk was found hidden under needle mulch on it's north side. For numbers, this dropped the level for average diameter breast high, added to the redwood's height, increasing girth slightly too. When measuring redwoods, hemlock, etc., I do not include any trunk under the soil surface. Only what's beneath fallen twigs, wood, leaves and needles.
The grove is mostly coast redwood with some western hemlock, a few Douglas fir and western redcedar. Sword ferns are abundant, vigorous and thick all over the place with the usual evergreen and red huckleberry. There are a few leatherleaf fern like the one on the lower trunk. A small bear trail runs through the area, but I haven't seen any trace of elk.
About age, I estimate 2600 yrs.. Some years ago, the smaller Del Norte Titan was estimated around 2300 yrs. by researchers. This redwood probably sprouted about the time
Nebuchadnezzar's Babylonian army breached the wall of Jerusalem.
A closing note. For those who like to preserve a few pritine areas, this is not the kind of discovery to bounce ideas willy-nilly with people you haven't met face to face or understand. That's how wear and tear started at other titans. Even sharing where you haven't found something is step closer to wear and tear.