Some basic principles on how to use a topographic map that describe briefly what a contour line is and rules that apply to them are as follows. This is not a do all guide so if you’re preparing for a hunting excursion on land you never hunted either get a guide or talk with your local DEC and they would be more than happy to get you the information you need.
Contour lines will never cross one another. Each one represents a separate elevation and elevation is determined by how far above or below sea level the point on the map is. I should say elevation is determined by two points on the map which represents different heights on the earth surface. Sea level is used as a basis to measure these points.
Most topo maps will define streams and rivers with a blue line, but a good rule of thumb to remember is streams will form a V shape on the map, the sampled elevations determine which way the stream is flowing. Knowing features about streams can help you while hunting deer by determining were deer will cross a stream. Plus when you are following a blood trail deer often head to a stream depending on where your shot entered.
Upstream is defined as in the direction opposite to the flow of a stream.
Downstream is defined as in the direction of or nearer to the mouth of a stream.
Mouth of a stream is where the water flows to, water flows from upstream to downstream and ending up in the mouth of the stream.
A series of closed contour lines represents a hill, mountain, plateau or oblong ridge. These closed lines form a circular or oblong shape. If there are series of small hatch marks inside the circle this indicates a depression.
The closer the contour lines the steeper the terrain. Spaced contour lines represent a small grade or gradual slope. Contour lines that are close to another line with one being doted represent an overhanging cliff. Repeated lines represent a ridge top or plateau.
The bold contour lines represent the hundred foot mark. Say for instance 1600 feet and 1700 feet are both bold the distance between the two of them is a hundred feet. The contour lines between the two are twenty five feet. So the contour line represents 1600-1625 feet, 1625-1650 feet, 1650-1675 feet and 1675-1700 feet. Check the diagram below provided for visual learners.
Two double dotted black lines that run parallel to one another represent a seasonal road usually need a 4 wheel drive vehicle to get through them. Two black lines represent a paved road. If the lines are not continuous it means the road is a dead end.
A solid red line represents a route and along the route the black squares represent houses. A red and white line represents a county road.
Check back next week on how to use a topo map to help you when your hunting deer. Understanding how to use a topographic map is fairly simple once you know the rules of the road. I know this guide has taught you the basics and to help you follow along in our next article about using topo maps to plan your next hunt. They are simply another tool in our arsenal to help us better understand deer movement.