Map symbols are small graphic images that stand for something else. They may be depicted by pictorial images, abstract combinations of points and lines, or tonal shading and color tints. For example, an explorer might show an Indian village by using a miniature picture of a teepee. The mapmaker often uses a key or legend to indicate what symbol matches what feature. The final step in the preparation of an explorer's map is selecting and applying geographical names that identify relevant features, landmarks, and places.
Geographical names are fundamental elements of maps.
They also provide important reference frameworks in our daily life. During the early history of America, explorers and mapmakers named many of our mountains, rivers, and towns. Today, these names form part of our cultural heritage and provide clues to the history of our country's settlement and people. Mapmaking in the Time of Lewis and Clark Two hundred years ago when Lewis and Clark set out to explore the Far West, the basic principles and techniques of scientific mapmaking were well established. As early as the second century A. D. the Greek geographer Claudius Ptolemy prepared instructions for the construction of maps using latitude and longitude as a geographical frame of reference.