Constants that change
I generally think of a typical mountain as being a constant. Weather and seasons change of course. But a visit to Mount Pinos a year or so from now will not be enough for the fallen tree to decay back into the soil and the meadow that had lovely flowers last spring is likely to have lovely flowers next spring.
Our old trail map created in the early 1990s and released in 1992 is now out of print and we have been working at making a new map. And in the process we have found things have changed on the mountain.
We have a couple of trails, like Outback, that can be revised to a better route because prescribed burns cleared out some brush. But we have others, like Meadow, where the brush has grown so much that what the old map showed as an easy to follow trail is now better marked as a "general direction" where a map and compass is advised.
Land use changes
When the 1992 map was created there was a private operator that ran a fee based ski trail system out of the McGill Campground. We had to account for that when we made a map of the upper mountain. That operation no longer exists, so we need to map that area differently.
The old map was based on 1980s era USGS quadrangle maps, local knowledge, tracing paper, ink pen and lots of drafting time. While local knowledge is still a large factor we now have GPS tracks, DEM (Digital Elevation Model) digital files and lots of fancy computer software to record, visualize and share our geo-referenced data.
We are not the only ones grappling with new ways of doing things. The advent of satellite based mapping and navigation caused the US Government to change from using the North American Datum of 1927 (NAD27) to the North American Datum of 1983 (NAD83). This changes the reference ellipsoid from which elevations above sea level are calculated. So while the old maps show Mount Pinos having an elevation of 8831 feet, the current official geodetic information shows it at 2695.5 meters or about 8847 feet.
Yay! Mt. Pinos is now 16 feet higher to better catch snow!
Well, not really. Just measured differently.
The Earth Really Changes
We may change how we measure the earth but the earth also really does change. Of particular interest to cross country travel in the mountains is magnetic declination, the difference between where your compass points and true north. Back when the old USGS maps we based our old ski map on were printed that was about 14.6 degrees. It is now 12.8 degrees, nearly a full 2 degree change. That two degrees can be a huge difference when navigating in a white out!
We have done a lot of survey work over the last year and especially over the last six months and this will be reflected in our new trail maps this winter. We hope they will be as useful and as accepted as our previous edition.
In addition, we have donated much of our information to the Open Street Map project so it can be used by others. One of those other projects using Open Street Map data is the Open Snow Map project. They, in turn, are working toward ways of making ski maps available in a variety of ways including smart phone applications.
Posted on October 10, 2013
Updated on October 13, 2013
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