Boulder: Evolution of a City has captivated newcomers, tourists, and longtime residents for years with its dramatic visual and narrative presentation of the birth and development of Boulder. In this updated edition, 322 photographs - more than 90 of them current - capture landmarks, buildings, major events, and quiet moments from the 1860s to 2006. Photographs showing the same locations at several intervals in history reveal Boulder's continuum from past to present.

Pettem devotes the first chapter to an introduction of the early photographers whose work appears throughout the book. Moving outward from the central business district as development did, each subsequent chapter focuses on a particular area in Boulder, with an introductory essay followed by historic and contemporary photographs with detailed captions.