BOISE, Idaho -

The effort to preserve the home of James Castle is now moving underground.

Archaeologists with the University of Idaho have started excavating around the artist's century-old Boise home to discover new clues into Castle's life.

The self-taught artist was born deaf and mute in 1899 and died in 1977. Castle's drawings were made with a sharpened stick dipped in soot and saliva. Some are in collections at the Philadelphia Museum of Art and the Museum of Modern Art in New York.

Mark Warner, chair of the Department of Sociology and Anthropology, is leading the team of students and alumni over the next week.

The city of Boise bought Castle's home in 2015 and is currently in the middle of a massive restoration effort to preserve the Idaho native's legacy.