The Writing Process: One Idea Leads to Another

I frequently discover ideas for a new books as I am working on other projects.  What is mentioned as a passing fact in one book later turns out to be the main theme of another project.  For instance, in my book, The Ancient Cliff Dwellers of Mesa Verde, I wrote a short section about petroglyphs, or rock art.  I was fascinated both by the stone images that had been carved into the rock and by the fact that they have endured for hundreds of years.  A few years later, as I was leafing through a publication that I receive as part of my membership in a local museum, I learned of a rock art site in the California desert where thousands of petroglyphs lined the canyon walls.   I arranged a visit and discovered the subject for a new book, Stories in Stone: Rock Art Pictures by Ancient Americans.   Of course, the book wasn’t just about petroglyphs, but the stone images provided me with  a theme that allowed me to discuss the people who made them, how they did it, and what the symbols may represent.
(Both The Ancient Cliff Dwellers of Mesa Verde and Stories in Stone are out of print.  You can look for them in your library.)