When did the conference the UNLV Runnin' Rebels are a member of begin operations?
1989–90 UNLV Runnin' Rebels basketball team: The 1989–90 UNLV Runnin' Rebels basketball team represented the University of Nevada Las Vegas in NCAA Division I men's competition in the 1989–90 season, and won the NCAA title under head coach Jerry Tarkanian. 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). Mountain West Conference:  The MW officially began operations in July 1999.
i don't know