Near the rim of the canyon, close to the town of Mesa de Guadalupe I found a juvenile tarantula underneath a moss and plant covered stone. Near the tarantula was also the cast-off exoskeleton (exuvia), which our daughter Alice mistook for a "broken" tarantula. Just a tiny piece of it is visible in the left bottom corner, see Rim of the Canyon for a separate photo of the exuvia.
This photo is part of the blog entry Rim of the Canyon which has a photo of the habitat and more information.