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I am planning for a trek in coming winters. Thats not a regular or a trodden trail, its more of an optimistic approach onto a mountain. All the information that I have says that I was never a route, but I intend to make an attempt over the slopes and screes, occasionally having to climb up a not-so-long sort of a patch.

How can use a contour map to decide which possible line to take?

marked as duplicate by Ben Crowell, Rory Alsop Aug 23 '14 at 18:39

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In places where the contour lines are closer together, the slope is steeper. Where the lines are further apart, the slope is gentler. In a spot where you see several lines merge together, that is a sheer drop-off. Avoid those, obviously.

Look for nesting Vs on the map. These are ridges, or possibly ravines. Water (blue) bisecting the V will tell you it is a valley. Through practice, I can pretty distinguish a ravine from a ridge in a few seconds. Sorry, I can’t describe a technique for that. * Perhaps I am recommending spending time poring over contour maps ;—)

Be aware of the scale of the map and the level of elevation change for the map. In America, the USGS topographical maps generally go with 20’ per contour line. Some use 6m, but the style is distinct. We also have some maps with 40’ contours done in the same style as the 20’. Read carefully. My brain is trained to see that style of map and see 20’ contours. I have gotten myself into some difficulty expecting the terrain to be not so bad, but finding it quite steep in 3-D.

Also, realize that because of the nature of maps, there can be an awful lot of terrain variety hiding between two contour lines. The scree slopes you mentioned will be quite irregular.

* Having thought this over, if you are planning an off-trail hike, definitely spend some time studying the contour maps. I would suggest enough time to be familiar with the major features of the locale, including possible departure routes.

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    Telling ridges from ravines, rule of thumb: if the V "points" uphill, it's a valley. If it points downhill, it's a ridge. – Bristol Aug 26 '14 at 10:05
  • And in order to tell if the terrain is going uphill or downhill, read the contour labels, i.e. the numbers next to the contour lines which indicate the elevation of the contour. Usually the labels are only present on every fifth contour so as not to clutter the map. – Techie_Gus Dec 5 '17 at 16:11

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