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View Full Version : McKenzie Mountain - what's the "true" elevation?



iAmKrzys
07-08-2018, 10:25 PM
I recently hiked McKenzie Mountain in Adirondacks and I noticed that there are sizable differences in quoted elevation depending on the source:

Wikipedia gives 3861 ft - apparently sourced from Adirondack Trails High Peaks Region, published by Adirondack Mountain Club ( https://www.amazon.com/Adirondack-Trails-Region-Forest-Preserve/dp/1931951055 )
OpenStreetMap has it at 3822 ft (I'm not sure as to the source)
Peakbagger.com shows 3832 ft referring NAVD88 model ( http://www.peakbagger.com/help/glossary.aspx#navd88 )

To add a bit of color my GPS has peaked at 3853 ft, but that's likely not too accurate.

Is this perhaps due to differences between elevation models? Even if so, 39 ft seems like quite a spread.

TCD
07-09-2018, 09:10 AM
Older topo maps show it at 1168m (3827').

But the ADK book is usually quite accurate, so there may be more to the story. Paging Tony...

Mohamed Ellozy
07-09-2018, 04:49 PM
I recently hiked McKenzie Mountain in Adirondacks and I noticed that there are sizable differences in quoted elevation depending on the source:

...
OpenStreetMap has it at 3822 ft (I'm not sure as to the source)
...



The 3822 ft elevation for McKenzie Mountain is (like many OSM elevations) from the GNIS (Geographic Names Information System), in this case dated 23 Jan 1980, so take it with multiple grains of salt.


Just found How accurate is the elevation data in the Geographic Names Information System Database? (https://usgs.gov/faqs/how-accurate-elevation-data-geographic-names-information-system-database-how-was-it-measured):


The elevation data in GNIS are not official.
Only the geographic name and locative attributes are official.

iAmKrzys
07-09-2018, 07:06 PM
Older topo maps show it at 1168m (3827').

But the ADK book is usually quite accurate, so there may be more to the story. Paging Tony...
TCD, thanks for your help! I'm really curious what you find out. Please share what you learn from Tony!

iAmKrzys
07-09-2018, 07:15 PM
The 3822 ft elevation for McKenzie Mountain is (like many OSM elevations) from the GNIS (Geographic Names Information System), in this case dated 23 Jan 1980, so take it with multiple grains of salt.


Just found How accurate is the elevation data in the Geographic Names Information System Database? (https://usgs.gov/faqs/how-accurate-elevation-data-geographic-names-information-system-database-how-was-it-measured):




You are right. I just did a little bit of digging myself starting with OSM history for the McKenzie Mountain (version 1 in https://www.openstreetmap.org/node/357570936/history#map=19/44.33623/-74.03217 had gnis:feature_id tag) and from there I got to the GNIS record that you have probably already seen: https://geonames.usgs.gov/apex/f?p=gnispq:3:::NO::P3_FID:956798

tgoodwin
07-10-2018, 08:41 PM
The 3,861 elevation is from the 1953 15' series of USGS topo maps that used 20' contours. Because that elevation was printed in black on the 1953 topo, it was considered a "checked elevation" derived from actually having an instrument on the summit. There doesn't appear to be any benchmark shown on the summit, but I accept that as the best elevation since the 1953 series of maps appear to have been done with more care than the more recent metric maps that had the elevation at 3,832'. I agree that this seems to be a pretty big discrepancy, but not nearly as great as some of the discrepancies between the 1902 maps (done without aerial photography) and the 1953 maps where Couchsachraga "lost" 180'.

iAmKrzys
07-10-2018, 09:56 PM
The 3,861 elevation is from the 1953 15' series of USGS topo maps that used 20' contours. Because that elevation was printed in black on the 1953 topo, it was considered a "checked elevation" derived from actually having an instrument on the summit. There doesn't appear to be any benchmark shown on the summit, but I accept that as the best elevation since the 1953 series of maps appear to have been done with more care than the more recent metric maps that had the elevation at 3,832'. I agree that this seems to be a pretty big discrepancy, but not nearly as great as some of the discrepancies between the 1902 maps (done without aerial photography) and the 1953 maps where Couchsachraga "lost" 180'.

Thanks very much for the detailed explanation! I bet elevation measured with an instrument is a lot more likely to be close to the "real" elevation than something interpolated from the contour lines. Perhaps one day someone will bring surveying-grade equipment and update that elevation, but for now 3861 feet seemed closest to what my GPS showed, although I do recognize that my hiking GPS can't be relied on.

TCD
07-11-2018, 08:43 AM
Thanks, Tony, for the info!