Perhaps the most common question we are asked, those few of us who do make geologic maps, is, simply, “What is a geologic map?” This query is often followed by “What are geologic maps used for?,” “Hasn’t it been mapped before?,” and, if the person is really inquisitive, “What do all those lines, colors, and symbols represent?”

It must be a puzzling sight - a lone geologist, often miles from the nearest road, looking at rocks, putting lines on a map or aerial photograph. One rightfully wonders what that person is doing. This online pamphlet answers these questions and points out the value and many uses of geologic maps.