NEXT TO THE small, rundown house at 5015 Eugene Street on the north side of Boise, Idaho, is a whitewashed clapboard shed. Inside, the walls are covered with peeling, puckered blue wallpaper decorated, incongruously, with sailboats. It might have been built as a chicken coop, or perhaps just for storage, but for 30 years it served as the studio and living space of a man named James Castle. He is the reason that, in October 2016, archaeologists, students, and volunteers arrived at the shed to excavate its dirt floor.
Castle was born in 1899 in the remote town of Garden Valley, in the mountains north of Boise, to a large, hardworking Irish Catholic farming family. He was profoundly deaf from birth, and despite five years at the Idaho School for…