McMillan was a member of the
Boise State Broncos of
Boise State College from 1971 to 1974 and a three-year
letterman from 1972 to 1974. He completed 74 of 136 passes (54%) for 1,027 yards, eight touchdowns, and seven interceptions in 1973. They were invited to the first-ever
NCAA Division II playoffs, where they beat
South Dakota 53–10 in the quarterfinals before losing to
Louisiana Tech 38–34 in the semifinals. In 1974, McMillan totaled 192 completions on 313 attempts (61%) for 2,900 yards, 33 touchdowns, and 15 interceptions while also rushing 90 times for 201 yards and two touchdowns. He was named the 1974 Big Sky Offensive Player of the Year and also named a Division II
All-American by the
Associated Press,
United Press International, and
Kodak. ==Professional career==