An elevation increase of approximately 6,800 feet occurred in the course of a hike to reach Red Peak Pass in Yosemite National Park, Calif.
Topographical maps are an indispensable tool for the serious hiker. Serious hikers are those who strike out into areas that, for all practical purposes, can be regarded as wilderness. Those who veer off established trails or take off on solo treks need to have a basic understanding of the use of a topographical map. Reading contour lines will help you plan a trip itinerary. Understanding how changes in elevation can impact your trip are essential.
Instructions
Read Contour Lines
1. Obtain 7.5 minute or 1:24,000-scale maps from the United States Geological Survey. This agency has been responsible for charting the country since 1879. A 7.5 minute map means that it charts an area of 7.5 miles east to west. It is the most detailed map available for a particular area.
2. Look closely at all those brown, numbered lines running all over the map. Those are contour lines. On a 7.5 minute map, the distance between the darker lines represents an increase or decrease of 100 feet in elevation. In between the dark lines are light brown lines. The space between these represents an elevation change of 20 feet. Basically, the closer together the contour lines are, the steeper the grade.
3. Determine a realistic mileage of a trip's itinerary based on your reading of the contour lines. This is especially important for overnight backpacking trips on which you intend to cover a certain distance over two or more days. Let's say that you have determined, either by distances stated in a guidebook or by rough estimate based on the map's mileage key, that you would like to set up camp at a point 7 miles from the trailhead. But, is it really just 7 miles?
4. Count the number of dark contour lines that the trail crosses. Let's say that a 7-mile trail crosses six of those lines. From a physical standpoint, especially for those carrying a loaded backpack, the distance is going to feel more like 7 1/2 miles. Change in elevation is the key here. The rule of thumb is that you add a mile to the distance for every decrease or increase of 1,000 feet in elevation on the route. For backpackers, it is just as demanding to go downhill as it is uphill. Gravity's drag makes no distinction.
5. Hone your map-reading skills through practice. Day trips of moderate length over established trails can give you a feel for how terrain looks in real life compared to what you see on the map. Over time, the meandering patterns of a map's contour lines will take on a more definite form in your mind's eye of what the terrain really looks like. You will eventually be able to identify particular valleys and canyons that are likely to have features like waterfalls or unusual rock formations.
Tags: contour lines, contour lines, contour lines will, established trails, feet elevation
