1953 (June-Sept.) Archaeological excavator at Vantage, Washington for the Department of Anthropology, University of Washington.

1954 (June-Sept.) Assistant Director of archaeological excavations at Vantage, Washington for the Department of Anthropology, University of Washington.

1955 (June-Sept.) Research assistant, Children's Hospital, Boston.

1956 (June-Sept.) Research assistant, Museum of Paleontology, University of California, Berkeley.

1960 (June-Sept.) Archaeological excavator at Les Eyzies, France for the Department of Anthropology, Harvard University.

1962, 1964 Teaching fellow, Department of Anthropology, Harvard University.

1964-66 Instructor, Department of Anthropology, University of Illinois at Urbana-Champaign

1966-70 Assistant Professor, Department of Anthropology, Harvard University.

1967-68 Visiting Fellow, Department of Demography, Research School of Social Sciences, Australian National University, Canberra.

1969 (June-Sept.) Visiting Assistant Professor, Department of Anthropology, University of Utah.

1970-73 Associate Professor, Department of Anthropology, University of Illinois at Urbana-Champaign.

1973-99 Professor, Department of Anthropology, University of Illinois at Urbana-Champaign.

1978 (Feb.-June) Visiting Fellow, Department of Prehistory, Research School of Pacific Studies, Australian National University, Canberra.

1999- Professor Emeritus, Department of Anthropology, University of Illinois at Urbana-Champaign.