Most of the trails are overlaid on topographic (or topo) maps. Topo maps are an attempt to show real variations in elevation on a flat map. If you know how to read a topo map, the map itself can tell you a lot. Here are a few tips to help you out:
- Contour lines are the brown lines on a topo map and can tell you a lot about the terrain. They show the elevation—the steepness or flatness of the land. The closer the lines are together the steeper the terrain; the more spread out the lines
the flatter the terrain. When contour lines are numbered, such as 3800’, land all along that line is 3800 feet above sea level. Contour lines follow the land formations such as valleys, which are marked by a V shape with the bottom of the
V pointing uphill.
- Black squares or rectangles represent buildings: houses, barns, businesses, schools (have a flag on top), churches (have a cross on top, etc.
- Blue indicates water and green indicates forested area. There are also symbols for wetlands, ponds and meadows.
- Most roads are indicated by a red line, a red and white dashed line or two black lines.
- If you see a symbol that looks like concentric circles with hash marks, it means a depression, such as a sinkhole. A concentric circular shape without hash marks indicates a high point, hilltop, knob, etc.
- For a full description of all symbols used on topo maps, visit www.usgs.gov and search for Topographic Map Symbols.