(Mike Easterling | The Daily Times via AP) In this Sept. 17, 2019 photo, a lengthy inscription by Phila Bliven covers the viga on the left side of this image in a room in the West Ruin at Aztec Ruins National Monument at Aztec, N.M. Her signature is visible at the top right of the viga. A Colorado historian is leading a team to survey the historic inscriptions on the ceilings of the 900-year-old ruins in northwestern New Mexico.