Rivers
If it's in a black circle, it's a heliport
Usually they indicate the borders between the states.
They are quite probably boundaries of some kind. Check the legend on the map to find out what kind of boundary they are.
Called both Elevation Lines or Contour Lines
usually it's state boundaries
Rivers
Isotherms and they are lines on a map that connect areas with the same surface temperature.
The black lines mean it is a state boundary.
thin black lines
In most cases the black lines which are between the states point out the border between different states, telling the map reader when the you are in a different state.
Contour lines on a map are typically brown or black in color. They indicate elevation changes on the map.
black
on a map,what do black lines between states usually represent? state boundries
the lines on the map is called longitude and latitude.
If it's in a black circle, it's a heliport
On maps, black lines between states represent boundaries or borders, where one state stops and the others starts. These are also called state lines.