In the 1930s, the anthropologist Greenville Goodwin classified the Western Apache into five groups (based on his informants' views of dialect and cultural differences): White Mountain, Cibecue, San Carlos, North Tonto, and South Tonto. Since then, other anthropologists (e.g. Albert Schroeder) consider Goodwin's classification inconsistent with pre-reservation cultural divisions. Willem de Reuse finds linguistic evidence supporting only three major groupings: White Mountain, San Carlos, and Dilzhe'e (Tonto). He believes San Carlos is the most divergent dialect, and that Dilzhe'e is a remnant, intermediate member of a dialect continuum that previously spanned from the Western Apache language to the Navajo.