The Southwestern United States is ideally suited for keeping secrets. Deep inside its mountains, behind barbed wire in its deserts, and in silos dug into its soil, the region hid more than its share of America's clandestine Cold War activities.

CNN Interactive's Andy Walton visited nine sites from the Colorado Rockies to the San Francisco Bay to visit the locations where the secrets are out, where the secrets remain, and where, in some cases, the prevailing question is: "What now?"

Click the interactive roadmap below for more on each of the destinations; or start with Cheyenne Mountain and use the navigation buttons at the bottom of each page to retrace Route Cold War.