When did the conference the UNLV Runnin' Rebels are a member of begin operations?
1989–90 UNLV Runnin' Rebels basketball team:  The team played its home games in the Thomas & Mack Center, and was a member of the Big West Conference; it would join the Western Athletic Conference in 1996 and become a charter member of its current conference, the Mountain West Conference, in 1999. Mountain West Conference: The Mountain West Conference (MW) is one of the collegiate athletic conferences affiliated with the National Collegiate Athletic Association (NCAA) Division I Football Bowl Subdivision (FBS) (formerly I-A).
i don't know