Atlas maps contain a variety of symbols denoting different types of roadways, from major highways to unpaved country roads. Interstate highways are shown in solid blue lines with blue shields topped with red crowns spaced along the route. White numerals in the middle of the blue field indicate the Interstate number.
U.S. highways, such as the historic Route 66, are denoted by a similar crown shape shaded all in white with black numerals indicating the route number. All principal highways are highlighted in solid pink lines.
On topographical maps, trails are shown in evenly sized dashed gray line segments. Trailheads, or beginnings, are marked with the stacked capital letters "TH" outlined in a red box with a white background and containing a red arrow. Wavy contour lines cover topographical maps, showing elevation. The closer a pattern of contour lines are to one another, the steeper the grade. More space between lines shows a flatter or more gradual grade.
Boundaries on most maps are displayed in a series of dashes and/or dots in various colors, depending on the type of boundary. On road maps, state lines follow an alternating long dash, short dash pattern in black.
On topographical maps, state boundaries follow a pattern of two small dashes, one large dash in a lighter gray color.
Be sure to consult specific map legends to decipher other types of boundaries and how they are denoted.
Several map symbols denote various modes of transportation, including railroad lines, airports and landing strips.
On atlas maps, airports are shown with a small blue airplane icon. Airports and landing strips on topographical maps often are denoted in sideways leaning, hollow white crosses outlined in gray.
Railroad lines on both types of maps are shown with a long line running the route of the tracks crossed in small perpendicular line segments resembling the tracks.
An array of icons show travelers where to find various services along travel routes. On road maps, service areas are marked with blue gas-pump symbols. Hospitals are shown with a blue box containing a white "H." Rest areas with bathrooms are shown as blue huts with trapezoid rooftops. Rest areas without bathrooms use the same icon but with a white empty box in the center.
On topographical maps, hikers can find picnic areas by searching for small picnic table icons along the trail. Small, red, tent-shaped triangles denote campgrounds, and red snowflakes show winter recreation areas.
Points of interest on a road map are marked with small pink squares. Parks are shown with small green leaves, and golf courses and country clubs are staked out with small red flags.
On topographical maps, small diamond-shaped outlines or dashed oval outlines show the location of sports fields, while solid ovals show racetracks.
