Topo Maps

Topographic Maps  

Topo Maps are used to navigate forests, and Topo Maps are used for elevational change. 

The earth is not 2D, but 3D dimensional. The earth is full of high spots and low spots.  

Looking at a 2D dimensional face and converting it to a 3D dimensional object. 

Contour Lines  

Contour lines are RED lines, and if the line is at 3000ft, that is where you are.  

Contour lines=Equal Elevation  

Different maps have different contour lines.  

Slope=

𝐸𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝐶ℎ𝑎𝑛𝑔𝑒𝐷𝑖𝑠tan𝑐𝑒Elevation ChangeDistan⁡ce

The more compacted the contour lines, the steeper slope  

NEVER cross other contour lines.  

Index lines are a bold and have printed elevation above sea level 

*Line MUST be going through the “X” 

Water goes into low spots and goes downstream.  

More depressions get filled with water 

Flat area= Smaller contour line  

Moutain area= Bigger 

If point of the “V” is pointing to higher elevation – valley, and “lower elevation” - ridge  

Gradient=

𝐸𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝐶ℎ𝑎𝑛𝑔𝑒𝐷𝑖𝑠tan𝑐𝑒Elevation ChangeDistan⁡ce

Grade=

𝐸𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝐶ℎ𝑎𝑛𝑔𝑒𝐷𝑖𝑠tan𝑐𝑒𝑥 100Elevation ChangeDistan⁡cex 100

Finding Locations  

Tier and Range  

Red square = Township  

Township is 6 miles by 6 mile square (not big) 

All of Illinois is landed out of townships 

Townships are the main governments in rural areas  

6x6=36  

Each section is broken up into a quart section 

Representative Fraction 

1:100,000 

1 cm on map : 100,000 cm 

1 cm: 1,000 m 

1 cm: 1km  

5.7 cm on ruler, 5.7 km in real life  

7 ¾ in : 3,000 ft  

7 ¾  

1 in: 387ft  

Line E=7.5 in x 387= 2.903 ft