Navigating the Wild: Understanding Forest Service Maps for Overlanding
When embarking on an overlanding adventure in the great outdoors, a reliable map is your best friend. In the National Forest, two types of maps come in handy: Forest Recreation Maps and Topographic Maps. In this article, we'll provide a summary of the key points from an informative piece from the Forest Service that sheds light on how to utilize these maps effectively for your off-road journeys.
Forest Recreation Maps: Your Forest Guide Forest Recreation Maps are comprehensive guides covering entire national forests. These maps offer a two-dimensional view of the landscape, highlighting essential features such as land formations, roads, water bodies, campgrounds, lakes, and trails. Here's what you need to know:
- Coordinate Systems: These maps employ two primary coordinate systems. The township grid divides the area into 36 square-mile townships, numbered from north to south and east to west. Latitude and longitude coordinates are also available, though less commonly used.
- Location Posters: You might come across yellow "location posters" or "K tags" that indicate your location by section, township, and range.
Topographic Maps: Unveiling the Terrain's Secrets Topographic Maps, often referred to as "topo" maps, provide invaluable information about the landscape. They incorporate contour lines that represent elevation, allowing you to understand the terrain's shape and form. Key points include:
- Contour Lines: Thin brown lines on topo maps connect points of equal ground elevation. Contour intervals, usually 40 feet for 7.5-minute maps and 80 feet for 15-minute maps, are critical for assessing terrain steepness.
- Coordinate Systems: Similar to Forest Recreation Maps, topo maps include the township grid, latitude and longitude, and the Universal Transverse Mercator (UTM) grid for metric measurements.
Understanding Declination for Accurate Navigation
- Angle of Declination: This angle represents the difference between magnetic north and true north, varying by geographic location. In California, the declination typically ranges from 15° to 17° east
- Compass Use: To compensate for declination, you can use various methods, such as projecting magnetic arrows on the map, using a compass with a built-in declination setting, or manually adjusting compass readings.
Navigating with Map and Compass 7. Traveling by Map and Compass: Learn how to orient your map to the terrain, place your compass correctly, and navigate towards your destination.
- Finding Location: Discover techniques for pinpointing your current location by taking compass readings to identified landmarks.
Obtaining Maps for Your Adventure
- Purchasing Forest Service Maps: Forest Service maps can be acquired from forest offices or regional offices. Availability details can be found on the National Forest Maps List.
- Getting Topographic Maps: These maps are often available at local engineering supply stores or stores specializing in outdoor gear.
- Online Maps: Apps like On X and Forest Maps offer great maps for your phone. Be sure to download them, however, before you head out into the backcountry!
Armed with this knowledge, you'll be better prepared to tackle the wilderness during your overlanding and 4x4 adventures. Happy exploring!