By Donny Hughes 
A route can seem short on a phone screen and feel quite different when you are walking it. The path goes through a valley, climbs the far side and comes back down a different slope. Before going on a hunting walk in a place you don't know take a few minutes to look at the shape of the land as well as how far it is. A topographic map helps you make sense of the terrain.
Find the contour interval first
The US Geological Survey says contour lines show the shape and height of the land. Each line connects points that are at the same height. Before you look at two parts of a route find the contour interval in the map details. That tells you the height difference between each line. Also check the units. A number without its unit is easy to get wrong when you switch between maps.
Now look at how close the lines are. On the same map and with the same contour interval, lines that are close together mean the land is steeper than lines that are far apart. This is a first idea of the slope, not a promise about how easy it is to walk. The map might not say much about loose rocks, wet roots or plants that have grown since the map was made.
Look at a part instead of the whole day
Pick one part between two clear places and follow it slowly on the map. Where does it go down? Where does it go up again? Write down one question you would like to know before walking that part. You could ask the landowner or guide whether a marked path is still there or if a crossing is safe to use. Keep the uncertainty visible instead of making an assumption from an unclear symbol.
The legend is important here. A path, a boundary and a stream can be hard to tell apart on a screen. Make the map bigger. Check the symbol. A line showing a path on a map does not mean you are allowed to use it. Check with the landowner or manager to confirm access.
Practice somewhere you know
Take the same kind of map on a short walk you already know and are allowed to do. Stop at a place where the slope changes and compare the land with the lines on the map. This is an easier way to learn than trying to understand everything when you are on a hard trip. You can focus on one thing without needing the map to answer all your questions at once.
If you use a digital map, make sure the area is still visible when your device has no connection. Keep the information you need to read the map, like the legend and scale. A screenshot that misses some of this might not be as helpful as it seems.
Use the map to ask questions
For a first visit, a cautious plan with clear landmarks is more useful than a long route across unknown land. Compare it with local advice, the weather and your own experience. Reading the lines is part of getting ready. It does not mean you don’t need skills to find your way or have a plan B. Start with a route that you can explain clearly, including where you plan to turn back.