| Year | Institution |
| 2019 | Claremont-Mudd-Scripps |
| 2018 | Claremont-Mudd-Scripps |
| 2017 | Claremont-Mudd-Scripps |
| 2016 | Claremont-Mudd-Scripps |
| 2015 | Claremont-Mudd-Scripps |
| 2014 | Claremont-Mudd-Scripps |
| 2013 | Claremont-Mudd-Scripps |
| 2012 | Claremont-Mudd-Scripps |
| 2011 | Claremont-Mudd-Scripps |
| 2010 | Claremont-Mudd-Scripps |
| 2009 | Claremont-Mudd-Scripps |
| 2008 | Claremont-Mudd-Scripps |
| 2007 | Claremont-Mudd-Scripps |
| 2006 | Claremont-Mudd-Scripps |
| 2005 | Redlands |
| 2004 | Redlands/Claremont-Mudd-Scripps |
| 2003 | Claremont-Mudd-Scripps |
| 2002 | Redlands |
| 2001 | Redlands |
| 2000 | Redlands/Claremont-Mudd-Scripps |
| 1999 | Redlands |
| 1998 | Redlands |
| 1997 | Redlands |
| 1996 | Redlands |
| 1995 | Redlands |
| 1994 | Claremont-Mudd-Scripps |
| 1993 | Claremont-Mudd-Scripps |
| 1992 | Claremont-Mudd-Scripps |
| 1991 | Claremont-Mudd-Scripps |
| 1990 | Claremont-Mudd-Scripps |
| 1989 | Pomona-Pitzer |
| 1988 | Claremont-Mudd-Scripps |
| 1987 | Claremont-Mudd-Scripps |
| 1986 | Claremont-Mudd-Scripps |
| 1985 | Redlands |
| 1984 | Redlands |
| 1983 | Redlands |
| 1982 | Redlands |
| 1981 | Redlands |
| 1980 | Redlands |
| 1979 | Redlands |
| 1978 | Redlands |
| 1977 | Redlands |
| 1976 | Redlands/Claremont-Mudd-Scripps |
| 1975 | Redlands |
| 1974 | Redlands |
| 1973 | Redlands |
| 1972 | Redlands |
| 1971 | Redlands |
| 1970 | Redlands |
| 1969 | Redlands |
| 1968 | Redlands |
| 1967 | Redlands |
| 1966 | Redlands |
| 1965 | Redlands |
| 1964 | Redlands |
| 1963 | Claremont-Mudd |
| 1962 | Redlands |
| 1961 | Redlands |
| 1960 | Redlands |
| 1959 | Redlands |
| 1958 | Pomona/Claremont |
| 1957 | Redlands |
| 1956 | Redlands |
| 1955 | Redlands |
| 1954 | Redlands |
| 1953 | Redlands |
| 1952 | Redlands |
| 1951 | Redlands |
| 1950 | Redlands/Pomona |
| 1949 | Pomona/Caltech |
| 1948 | Pomona |
| 1947 | Redlands |
| 1946 | Redlands |
| 1945* | -- |
| 1944* | -- |
| 1943 | Redlands |
| 1942 | Redlands |
| 1941 | Redlands |
| 1940 | Redlands |
| 1939 | Redlands |
| 1938 | Redlands |
| 1937 | Redlands |
| 1936 | Redlands |
| 1935 | Redlands |
| 1934 | Redlands |
| 1933 | Pomona |
| 1932 | Occidental |
| 1931 | Caltech |
| 1930 | Occidental |
| 1929 | Occidental |
| 1928 | Occidental |
| 1927 | Occidental |
* No competition during these years.