Preparing for a Hike Using a Topographic Map

Preparing for a Hike Using a Topographic Map
If you're interested in exploring areas of wilderness off the beaten path, or perhaps with no path at all, then you will need topographic maps to guide you. These maps offer highly detailed depictions of terrain by creating a three-dimensional impression with contour lines. These lines not only show the rise and fall in elevation but can offer a hiker clues as to which direction a stream flows, the easiest way to ascend a peak, and which areas to avoid all together. Originally produced by the United States Geological Survey (USGS) for the sake of mining and land use, "topo" maps covering the whole country are available to the public for recreational purposes, so take advantage of them when planning your next excursion.
 

Instructions

Difficulty: Easy

Section 1: Reading the Map

Step 1
Familiarize yourself with the symbols. The first time you look at a topographic map, it can seem a little daunting. The three main colors you will see are green, blue and white (sometimes tan). The green represents areas of dense vegetation, the blue represents bodies of water, and the white represents areas without forest or thin vegetation areas.
Step 2
The other common element to topographic maps is the curving, thin brown lines. These contour lines cover the entire map like ridges in a fingerprint and they specifically separate a topographic map from any other type of map.
Step 3
Look at the distance between brown lines. The farther apart they appear, the more gradual the change in elevation; the closer they are to one another, the steeper the climb or fall. Contour intervals will always be consistent in distance and on USGS maps, every 100-foot change in elevation will be marked by a brown line that is thicker than the others and it will give the exact elevation. Peaks of hills and mountains will appear as an "o" like the center of rings on a tree and they designate the highest point.
Step 4
Look at the key on the map. The key will help you decipher any other symbols you will see. Generally, borders are marked by dotted black lines, trails appear as thin black lines, and roads are thick red lines or hollow black lines.
Step 5
The most important element of the key is the scale. All topographic maps are created with a scale in mind; generally USGS maps are created at a 1:63,360 scale, meaning that 1 inch on the map represents 1 mile. When planning a trip, knowing the exact mileage you intend to travel will inform the amount of clothing, food and gear you bring, so it is essential to understand how to read the mileage of your route before starting a trip.

Section 2: Planning a Trip With a Topo Map

Step 1
Plan to take the flattest route possible. Trails usually follow this rule anyway, so it's a relatively easy task if you stay on the path; however, if you are looking to do some off-trail hiking, remember that it's much easier to draw a line across a map than it is to actually hike it, particularly in mountainous terrain. Pick the route with the least amount of rise or fall in elevation, meaning the topographic lines are spaced generously from one another. If you are ascending a peak, choose the route with the most gradual climb or you may find yourself in a tough situation without the proper gear.
Step 2
Plan to take the lowest elevation route possible. If you are organizing a trip that is several miles long and crosses over mountain ranges or other big rises and falls in terrain, plan to keep a constant elevation. Find the lowest points between peaks, called saddles, to cross a mountain range. Instead of dropping into valleys only to climb another steep grade, traverse across the side of a peak, following one of the topographic lines. This will not only help you avoid pulmonary edema and other afflictions associated with altitude sickness, but it will keep you at a steady pace.
Step 3
Streams and rivers always follow the lowest path between hills and mountains, so choosing a path that follows a stream will keep you at the lowest elevation; however, keep in mind that these areas will also sometimes be the steepest, so find a balance between Steps 1 and 2.
Step 4
Map the distance you will travel. Unlike driving, your path usually won't be a straight line. Instead, mark the distance of a mile on a string according to the key (usually an inch). Then, use the string to trace the twists and turns that you will have to take in order to negotiate the terrain. In mountainous areas, the distance between two points is almost always much farther than it looks.
Step 5
If your trip is going to take place over several days, plan to camp near water and below timberline. Streams and lakes will provide you with water for cooking and re-hydrating (as long as they've been treated), and camping below timberline, or the elevation where trees cease to grow, will ensure that you have some coverage in a storm as well as slightly warmer temperatures. Water is easy to spot on topographic maps, and you can distinguish timberline by sticking to green areas.
 

Tips & Warnings

 
Determine the flowing direction of a stream by the shape of the topographic lines. The lines will create a "V" that always points uphill.

Article Written By Soren Bowie

Soren Bowie has led hiking and camping trips across the White River National Forest in Colorado. He was a competitive snowboarder and rock climber from 1998 to 2000 and has extensive knowledge in outdoor survival skills, from avalanche safety to orienteering. He currently makes a living in Los Angeles, California as a writer and an editor for numerous online publications.

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