Marion Mountain "Wrong" on the Map?

[Hikin_Jim]

So, this has been bugging me for a while, but it looks like Marion Mountain's summit is incorrectly marked on the USGS topo map. What I mean is that the position of the spot elevation (designated by an "X" and the number 10362) on Marion Mountain does not appear to be the high point of the peak.

Take a look at this graphic:


Note that the summit ridge of Marion Mountain has an east-west orientation and that the spot elevation is positioned on the eastern portion of the summit ridge.

Now look at this photo of Marion Mountain, taken from Folly Peak. Note that the highest point appears to be on the western portion of the summit ridge, approximately where I've placed the hand drawn black dot on the above map.


Basically, what we've got is this:

The marked (spot elevation) high point is on the east, but the actual high point is on the west.

Have I got that right? Am I mis-identifying my features? I don't think so, but there's a full discussion on my blog.

Disagree? Great, but tell me why.

HJ

[hvydrt]

I have noticed several peaks like that. I wonder if it has to do with line of site when the surveyors were mapping the area?
other examples I noticed locally:
Mount R
Mount Edna

[hvydrt]

Also, to confuse things further, the GNIS detail page for Marion Mountain shows the location as 33.7958525, -116.6866838 (10362 spot elevation on the topo) but shows the elevation as 10335.

[jfr]

The official topo map appears to be wrong. My gps track from 2011 shows my wanderings all over the summit (I climbed all three summit blocks, even though the middle one is obviously lower than the other two), and the track clearly indicates that the official high point on the topo map is the eastern peak and that your black dot is the western peak.

The cemented remains of the old summit register box are on the western peak, so that leads me to believe that it is higher. It's certainly the more fun summit block to climb. Why did I climb both the east and west peaks? Because I, too, wasn't sure which was the "real" peak.

Interestingly, when I sat on the western summit block, I looked east and the eastern block appeared to be higher than the far distant horizon. Obviously, that meant that it was higher than my head, and my head was several feet above the rock I was sitting on. Good logic, right? So I walked over and climbed the eastern summit block. And, lo, the western block ALSO appeared to be higher than the distant horizon! How could this be? Was this like the fabled grandfather that walked to school uphill both ways?

Methinks the earth doth curve too much...

[Florian]

Interestingly, when I sat on the western summit block, I looked east and the eastern block appeared to be higher than the far distant horizon. Obviously, that meant that it was higher than my head, and my head was several feet above the rock I was sitting on. Good logic, right? So I walked over and climbed the eastern summit block. And, lo, the western block ALSO appeared to be higher than the distant horizon! How could this be?

Because the Earth isn't flat, silly.

-Florian

[Hikin_Jim]

I have noticed several peaks like that. I wonder if it has to do with line of site when the surveyors were mapping the area?
other examples I noticed locally:
Mount R
Mount Edna

Interesting. A mountain named "R." I wonder what the story is there?

I do note that Edna and "R" are triangulation points, meaning that they were shooting bearings in conjunction with those points. Line of sight to particular other points would be important.

With Marion Mountain, it's not a triangulation point; it's just a spot elevation. It's just interesting to me that they chose that spot and not the highest point. The highest point is fairly obvious.

By the way, I "saw" you in the summit register:


HJ

[Hikin_Jim]

The cemented remains of the old summit register box are on the western peak, so that leads me to believe that it is higher.

Oh, you mean like this?

Why did I climb both the east and west peaks? Because I, too, wasn't sure which was the "real" peak.

Actually, for me at least, there is no confusion. Having stood on the various high points atop Marion, it's very obvious to me that the western summit is the highest.

In making the call that the western summit is the highest, I rely on the facts that
1) It's fairly obvious at least to me that the western summit is highest when I'm physically atop it.
2) The western summit has the register.
3) The western summit has the distinctive crack system that descriptions of the ascent all mention.
4) Both the HPS and RMRU accept this as the high point.

I've also photographed the summit block from multiple angles. From every angle, the western summit is clearly higher. Here's a typical photo, taken from the flanks of Shirley Peak:


There's no doubt in my mind that the western summit is the highest point on Marion Mountain. I'm just a little bit curious as to why the surveyors picked the eastern summit to calculate a spot height on. Maybe they didn't like third class rock?

HJ

[Hikin_Jim]

Also, to confuse things further, the GNIS detail page for Marion Mountain shows the location as 33.7958525, -116.6866838 (10362 spot elevation on the topo) but shows the elevation as 10335.

Now that's just plain weird.

Interestingly, the point when I plot it on Acme Mapper is not exactly where the spot height is.

HJ

[hvydrt]

A mountain named "R." I wonder what the story is there?

I think its called Mount R because there is a giant "R" on the Southwest ridge. I assume it stands for Redlands.

Another guess at the official USGS summit location would be that the west and middle summits are just piles of rocks that have been weathered from the mountain and the spot elevation on the topo is solid rock, not a weathered, detached pile of rocks? Just a guess. Though if that was the standard for determining the summit, San J, San G, and hundreds of other peaks would be at a lower point on the map than the actual highpoint. I really doubt its a mistake, there has to be a reason that is the official usgs summit even though its lower than the middle and west summits. Considering the first calculation of the height of Mt. Everest in 1856 was only off by 27', you would think the 1976-1981 data for the topo in this area must be very accurate.

[Hikin_Jim]

I think its called Mount R because there is a giant "R" on the Southwest ridge. I assume it stands for Redlands.

Ah! Interesting. And the letter has become the full name of the peak.

I really doubt its a mistake, there has to be a reason that is the official usgs summit even though its lower than the middle and west summits.

Probably it was "Miller time" and the guy wanted to get back to camp. In the 1930's when the original survey work was done whoda thunk that some idiot named Hikin' Jim would care about which peaklet was the high point of Marion Mountain?

HJ