Nathan Otterson returned to the Guggenheim in 2005. He focuses on scientific documentation and treatment of the Guggenheim Museum’s modern and contemporary sculpture collection. Most recently he has concentrated on the treatment of works by Matthew Barney, Joseph Beuys, Maurizio Cattelan, Amedeo Modigliani, and Alexander Calder. He is currently researching Calder red paints from the 1950s, the mounting methods and deterioration of Richard Serra rubber works, the bases used on Modigliani heads, and surface finishes found on Constantin Brancusi sculptures. Otterson also oversees complex installation projects and exhibitions, which include objects created in a wide range of materials and working methods. Recent exhibitions at the Guggenheim have included Louise Bourgeois, Cai Guo Qiang: I Want to Believe, and Maurizio Cattelan: All. Otterson received an MA and a Certificate of Advanced Study in art conservation from the State University of New York, College at Buffalo, and a BA in studio art and communication studies and theater art from Concordia College, Moorhead, Minnesota. Prior to his current employment at the Guggenheim, Otterson held positions at the Walker Art Center, Minneapolis; the Museum of Fine Arts, Boston; the Guggenheim Museum; and the Midwest Art Conservation Center, Minneapolis. He has completed internships at the Brooklyn Museum; Central Park Conservancy, New York; and Gordion Excavations, Polati, Turkey.