How Much Detail  

Don't map everything. Image yourself as an orienteering, and map features that would be essential for navigation. Also set some minimum standards for yourself, such as, "I'm going to map every boulder over 3 meters tall." 

 It is possible to have too many objects on the map; a cluttered
map is difficult to read. The mapper should limit the number of
drawn objects to those that are necessary to a runner's
navigation. There are three criteria for putting detail on the
map:

 (a) would you hang a control flag on it?

 (b) would you use it to navigate?
 Think of the area from a runner's perspective.

 (c) would it impede your progress?
 The orienteers goal is move as quickly as possible between
controls flags. Any object that slows or diverts a runner should
be mapped.
 

Preparation - The Fieldwork Sandwich

The basic fieldwork sandwich is a base map sandwiched between a map board and a piece of tracing paper.

You'll need a base map at fieldwork scale, not map scale. This should probably be 1:7,500 scale. A larger scale will allow you to draw too much detail. You will need four colored pencils: black, red, blue, and green, and maybe orange. Yellow does not show up well in fieldwork.

For a map board, buy a cheap piece of Plexiglas from Home Depot for $3 - get a 16x24 piece. You may want to mount a compass on the Plexiglas map board as well.  Put a scale on the map board that converts from paces to millimeters at 1:7500 (or the scale you are using). This will make it easy to convert from your pace to a distance on the board. Surveyors refer to this board as a "plane table".

Mount your base map on the board using drafting tape; masking tape is too sticky. Cover this map with a piece of vellum, a kind of tracing paper. Good quality vellum is made from Mylar. Use "single tooth Mylar" which is rough on one side only. Mount the rough side up, so that you draw on the "tooth". The Mylar film does not expand with humidity and stands up well to drawing and erasing. (Note: Sam recommends a brand of Mylar-type film called Herculene 3 mil. single matte film)

Draw the grid on your Mylar so you can match it to the grid on your base map. They should have the same grid, so you can match the fieldwork to the OCAD map when you scan it into the computer.

What You'll Do

In the field, draw features on the vellum, using black for buildings and trails, red for contours and cliffs, blue for water features, and green for vegetation. Fields, that are yellow on the finished map, can be drawn in orange. Some mappers use green for fields, then make notes for distinction. The vellum with field notes will be scanned into the computer to be used as your new template. 

Another method is to use the red pencil for contours, brown for other earth features. Instead of coloring in green and yellow, draw around the areas with black, then label it - LG for light green, MG for medium green, DG for dark green, O for open, RO for rough open, OT for open with trees, ROT for rough open with trees.

Please take some time to review the "International Specification for Orienteering Maps". This document contains specific information and good advice on what to include on your map and what level of accuracy is required. You don't have to map every detail. Your map should be accurate enough that an orienteer using a compass and pacing would not notice any map errors.  

Define Your Standards the Start Walking

Don't just walk off into your new map and start drawing. Try to get a feel for the area to map. Which areas will be dark green? Which areas will be light green? What size rootstocks will appear on the map? How big a boulder will be mapped?

Enclose small areas with trails/streams/roads, etc. then work inside these areas. Constantly check back with areas you have already done. You may have to do vegetation last.

Mapping a trail quickly:

1. Accurately determine your starting point.

2. Orient the map board and sight across the board to the next curve. Lightly draw a STRAIGHT line in that direction.

3. Pace off the distance to the curve. Use your scale to convert to mm, and place a dot at this distance.

4. Look back toward your starting point. Align the board again.  Now draw in the curve of the trail. Be aware of the foreshortening and don't exaggerate the curve.

Repeat steps 2 thru 4 as required to draw the length of the trail. Every time you cross a stream, the bottom of a reentrant, or the top of a spur, mark it on your trail as a reference point.  When the trail reaches a known point then check your map's error. The amount you are off is called by surveyors the "Error of Closure".

Mapping linear features like a gully or stream:

1. Stand in the feature.

2. Align the map.

3. Sight up/down the feature.

4. Draw a light straight line.

5. Pace it off.

6. Mark the distance, align the map, look back and draw in the small curves.

There are other things you can map as if they were linear features:

Reentrants/spurs:

Treat them like a linear feature if they are sharp enough. Draw a light line down the bottom of the reentrant or along the crest of the spur. This line will serve as a guide, but will not appear on the finished map. Pace it off to the next junction or curve. Draw the curve of the feature. Go back and look level - draw in the curve of the contour.