So I found this two-and-a-half-year-old blog about the 1978 disappearance of Christopher William Vigil, a nine-year-old whom I assumed had simply gotten lost while hiking with his family in the Poudre Canyon in Colorado.
Having looked at this blog, however, Chris’s case is starting to look more and more like an abduction. I have dutifully updated his casefile with info from the blog, but invite readers to have a look at the source, which has more details.