In 1948 and 1949, Steere studied effects of naturally occurring radioactivity on plant life at Great Bear Lake and in Alaska.

[5] Steere, starting in 1950, spent eight years at Stanford University as professor and dean of the Graduate Division.

Between 1954 and 1955, Steere took a sabbatical from Stanford and accepted a one-year position with the National Science Foundation as Program Director in Systematic Biology.

[6][7] Steere assumed the title of Senior Scientist in 1973, before formally retiring from the Garden in 1977.

[8][9][10] As President Emeritus, however, Steere continued his bryological research at the Garden until his death on February 7, 1989.

1973 (Metzgeriaceae), Steereochila Inoue 1987 (Plagiochilaceae, listed as doubtful genera[11]), and Steereomitrium E.O.Campb.

[5] The Garden has also established the William Campbell Steere Fund to help bryologists who wish to visit their herbarium and library.

[16] In 1972, he was awarded the Order of the Sacred Treasure from Emperor Hirohito for his work on the US-Japan Cooperative Science Program.