Showing posts with label navigation. Show all posts
Showing posts with label navigation. Show all posts

Friday, September 24, 2010

Topo Maps and Profiles



Navigating and understanding land forms and profiles is a skill I'm working on this winter. Years ago I obtained this Forest Service Map of a local section of national forest which is very diverse in rivers, gorges, saddles, cliffs and waterfalls. The photo below is of a profile I've done to compare visual concepts mathematical tools.

Depending on the graphing gradients used, a trail can appear either quite difficult (the yellow line) medium in difficulty (green line) or fairly benign (red line). I really noticed this discrepancy in perception while hiking the Appalachian Trail. Most data was presented with the same markers and gradients until we reached Maine. Then, the profile seemed to be so horrendous, appearing as though it were impossible. With more careful study, one could see the miles were placed close together, while the elevations were space out on the vertical graph. Thus, to climb 400 feet in one mile appeared daunting. Had the miles been spaced further apart on the horizontal line, the climb would appear less formidable.


Lesson: always find the map key for numbers critical to the true picture.

This topo map has the contour lines marking at 20 foot intervals. Each dark line represents 100 feet. The closer they are together, the steeper the slope. But, because each block represents a square mile, one can see that the area has many gorges and slopes in a given mile. A map of Kansas, for instance would show very few contour lines.


I've found some trails and old logging roads in the area that are not recorded on this map. I have begun to pencil them in. A compass is essential in this work to keep it real. Also, some trails shown on the map have ceased to exist due to abandonment.


Some trails have an occasional hunter or horseback rider. For the most part, there have been no signs of motorized vehicles. No trail sign has been found indicating wheels of any sort.
These skills are useful if a person gets disoriented in the back country. Finding the way down stream to larger streams, learning to hike a straight line in a challenging terrain (keeping the sun at one's right shoulder for instance) is very interesting.
I always bring a compass, knife, flint, and large plastic bag in my pack just in case.

Friday, August 6, 2010

Rock Ducks

On my days off here in Zion, I like to hike early mornings. One morning I decided to do a little off trail exploring, back by the Sand Bench Trail. I bring my water bottle, some chlorine for water treatment, sun screen, and hiking poles.

This trail is fairly difficult walking because the horses create a "trench" of fine sand. I wear long pants, not shorts because of the prickers and dirt that gets in the socks and shoes when wearing shorts. Even with this protection I still end up with cactus thorns in my lower legs, which must be removed as soon as possible.

Amazingly, while off trail, I found a series of rock ducks. These man made landmarks are handy and totally harmless to the planet. The smaller ones I add a rock to, and build a few more along the sketchiest stretches.

Now, actually, I didn't tell anyone where I was going this morning. So, if I would break a leg in this scramble, it might be awhile before anyone found me. I come prepared for this eventuality with the stuff I carry in my pack, and take my time in the loose rock and steep climbs.

As they say, what goes up must come down. Gravity sees to that.

But, what goes down, doesn't always get back up. The Grim Reaper never sleeps.