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determining the location of a summit

PostPosted: Fri Oct 15, 2010 9:14 am
by JoeGrim
John, I'm kind of curious of the rule you used to determine the location of a summit, especially when there is a difference between the most prominent and the highest point of a named feature. Now, I would guess that 99% of the time, they are one and the same, but I've run across a few where they are different.

Example 1: Elk Ridge in Larimer Co., CO.:
The highpoint of the ridge is 8766' here: ... .4184&z=15
but the most prominent point on the ridge is 8580' here: ... =-105.3680
You have the most prominent point marked as the summit location.

Example 2: Dick Ridge in Rio Blanco Co., CO:
The highpoint of the ridge is 7642' here: ... =-108.0927
but the most prominent point on the ridge is 7121' here: ... .1071&z=15
You have the highpoint marked as the summit location.

Until recently, I had thought it was the highest point with prominence that you used, but now I'm wondering if it is the most prominent point. Or maybe it's a rule I haven't thought of. Or maybe you just had to make a personal judgment call in these rare instances. Anyway, I'm just curious. Thanks for the ever-improving summit resource you have here at LOJ!

Re: determining the location of a summit

PostPosted: Sun Oct 17, 2010 6:56 pm
by TWorth
Hi Joe,

Having helped work up a few of these lists on this site I'll take a crack at your question. John correct me if I am wrong on any of this.

Both of your examples are ridges with less than the required amount for prominence for automatic listing. It's a judgement call as to the "summit" location with those, basically the idea is to make a determination of how far the ridge extends before morphing into an actual mountain and find the highest point on the ridge for the location. Points with some sort of prominence along the ridge are given preference over points on a slope, but there wasn't an effort to seek out the spot with the most prominence on a ridge necesarily, especially if there was a higher spot somewhere else on the ridge.

As far as I can tell, this sort of approach is consistent with the original 13er/12er CO lists developed by Garratt/Martin/Nolan/Roach/others as far as unranked ridgepoints go. If I recall the G+M High 13ers book goes in to some details on the named ridge subject. In extending the CO lists the idea was to work within the framework that was already developed rather than reinvet the wheel.

With Elk Ridge, its true, the summit could be construed as the 8766 point. Or is that point just a subsummit of Panorama Peak? Its about the same distance from the peak to the Elk Ridge label on the map.

A similar example in the 12ers in Jacque Ridge, its listed at 12432 despite there being a 12660 point nearby. It appears that's a case where location was based off the label on the map.

This is one advantage to using a ranked crietria in that it's based on an objective measure irregardless of how a peak or ridge is labeled on that map or some sort of subjective criteria.

OK, that's enough of a dissertation for one post :toothless: . Hope this helps...this stuff is a bit arcane but it had to be considered when organizing the geographical data on this site.

Re: determining the location of a summit

PostPosted: Mon Oct 18, 2010 7:36 am
by JoeGrim
Thanks for your thorough explanation, Tim!