Since the early Manuals of Instruction were not specific insofar as where the measurement was taken (center of tree vs. blaze) has it historically been assumed that the measurement was to the center of the tree at the root crown? The 1973 and 2009 manuals (4-85 and 4-81 respectively) state the horizontal distance is counting to the center of the tree at its root crown. (When creating new BT's). The actual diameter of the tree is taken at breast height.
The measurement, unless specifically noted on new BT's, would then be to the face at root crown plus half the diameter taken at the root crown? If only two bearing trees are found in adjacent quadrants, the distance-distance measurements could then yield two different positions for the corner position depending upon where the measurements were taken.
It has also been stated to me that mineral survey BT's are usually measured to the face of the blaze, sometimes marked with a nail in an "X". Also, that Juniper bearing trees can be found with the scribes on a horizontal limb 5' or more above the ground.
Not being in an area where surveyors recover bearing trees or create new ones, I am curious what others have to say on this topic.
Having performed alot of retracement, I have found MORE that were face measurements, than center of root crown.
The logic for this is:
I measure 10' to the face of a 12" Pine. Thus, we know that it is 10.5' to the middle.
I am not saying anything about what the BLM says, etc, I am just saying that I have found more that followed the above logic, than measurement to middle base.
Another injected problem then persists, "Was the tree leaning, or crooked". I always measure to the MIDDLE at the estimated stump hole, if that was all that was left.
Just from experience.
N
Not in PLSS, but around here when there are BT's (generally National Forest or National Park) we generally assume the middle of tree unless the contrary is shown.
However, if I find an old nail at the blaze I definitely consider the nail as the point of measurement.
My experience and both direct and indirect is that it depends a lot on the age of the survey record.
Older surveys are more ambiguous as to face vs center. More recent GLO surveys tend to be to the center.
Many older GLO surveys such as you find in the SE US PLSS states seem to have cases of measurements to the face.
The only way to tell is by testing your assumptions against material evidence on the ground.
As a general rule you can probably never fully trust any assumption without a test. That means you might have to do some non minimalist retracements where you have identified original monuments and some BT's. The more you have, the more it will become clear what the practice was for that deputy in that survey.
Now another complexity for you.... What about the rare but not non existent situation where the BT is something like a juniper where a horizontal limb was scribed. And that blaze is no where near the bearing to the trunk? Was distance taken to the blaze or the trunk? Another question that can only be solved by careful analysis and often judgment.
Another item that may affect your thought process is if the distance to the BT was truly horizontal or taken as a direct slope distance to the blaze or tree at that location.
Intuition tells me that cornermen may not have gone overboard to hold the chain horizontal in all situations.
My vague memory tells me that mineral surveys may have tended to be slope distances rather than horizontal, but I have nothing to back that up.
- jlw
My recent CFEDS studying states that "generally a PLSS bearing tree is measured to the center of the tree."
Jerry:
One of my old mentors and employer that was a former GLO Cadastral Surveyor in the 1930's told me that they measured to the face at the approximate center of the blaze on the bearing trees. But, I can't recall if he said they measured on the slope or horizontal though.
> Jerry:
>
> One of my old mentors and employer that was a former GLO Cadastral Surveyor in the 1930's told me that they measured to the face at the approximate center of the blaze on the bearing trees. But, I can't recall if he said they measured on the slope or horizontal though.
I worked with a BLM Re-monumentation specialist on 119 Section and HES monuments and 10 years on a USFS cadastral crew; all were measured to the center of the tree or the center of the tap root.
After retracing several hundred Mineral surveys; they mostly went to the face of the blaze.
My $0.02
I always figured that in the old days, there must have been a reason why they called it a "chaining notch" (like maybe they "chained" to it).
So all things being considered (and of course ALL THINGS MUST BE CONSIDERED!!!!!!!),
IF nothing else points me to the contrary, I use the face of the blaze or if possible, the notch itself. 😉
Geezer
"My recent CFEDS studying states that "generally a PLSS bearing tree is measured to the center of the tree."
In my area I have found this to almost always be the case, although there are Forest Service corner record cards that indicate that they may have measured to the face of the blazes they created during the middle of the last century.
I've seen it done both ways. Too the face and to the center. It's always nice finding a rusting nail that was used to measure off of. Reminds me a bit of the way witness distances are stated on various plats. The GLO/BLM surveys nearly always call out the total distance and then one needs to subtract out the WD to get to the witness corner while the State's plats would call out the distance to the witness corner and you'd then need to add the WD to get to the true corner. Different strokes for different folks I guess. Be tough to know one way or another if all you had one BT to go of. :-/
Just because I'm paranoid, doesn't mean they aren't out to get me.
Hard To Prove With Only Two Ties
Assuming one is trying to reset a missing corner.
With three ties it should be reasonably easy to prove mathematically which method was used if three existing bearing trees can be located.
Given I can only find two ties I would be comfortable using the exact same method I can show was used on the nearest adjacent found corners.
"Gather your evidence and form an opinion."
Paul in PA
Obviously no simple answers. A lot of determinations can happen on the ground in real time if your experience & the evidence allow. Sometimes it can help to do a thorough job of mapping, in 3D, the accessories, blazes, etc. to dig into possible measurement patterns in the office, all depends.
I Retraced 3 sections once, a relatively early contract where GLO allowed 2 different deputy surveyors, they later stopped joint contracts though. Virtually every 2nd BT was measured at an exact interval of 10 links, quite often wrong species, always gross diameter issues. At section corners if 3 or more BT's were available it sorted relatively well, for 1/4 or witness corners not so easy.