<P> Oregon and Oregon State joined in the summer of 1964 . With the addition of the two Oregon schools, the conference was known unofficially as the Pacific Athletic Conference, and then the Pacific - 8 (as there already was a major conference called the Big Eight). In 1968, the AAWU formally renamed itself the Pacific - 8 Conference, or Pac - 8 for short . The Pac - 8 did not allow a second bowl team from the conference until the 1975 season . </P> <P> Idaho was never invited to join the AAWU; the Vandals were independent for four years until the formation of the Big Sky Conference in 1963, and were independent in football until 1965 . </P> <P> In 1978, the conference added Arizona and Arizona State from the Western Athletic Conference, becoming the Pacific - 10 Conference or Pac - 10 . The invitations to the schools were extended in December 1976, and the expansion formally announced in May 1977 . </P> <P> In 1986, the Pac - 10 began sponsoring women's athletics . Prior to this time members' women's teams competed with other large universities on the Pacific coast in either the Northern Pacific Conference or the Western Collegiate Athletic Association . </P>

When did the pac 8 become pac 10