Excavation crew working in suffocating dust of Fate Bell Shelter in 1932. This problem has been faced by all excavators. The modern practice of sifting (screening) the soil has only made things worse. Dust churned up by the 1932 work and subsequent uncontrolled digging still adheres to the wall of the shelter and obscures the once-plain pictographs. Photo from ANRA-NPS Archives at TARL. |