He contributed to the team reaching the Class 2A State Championship in the 3 years he played, helping the school winn two of them (1966–67 and 1967–68).

He is recognized as the greatest tight end in Michigan State history, even though he had few opportunities to prove his true worth in the Spartans run-oriented offense.

As a junior, wide receiver Gordon Bowdell left for the NFL and Dupree took over as the leader of the passing offense.

Although the Spartans ran the Wishbone T offense and he was required to focus mainly on blocking, in a team that only completed a total of 44 passes, his 23 catches for 406 yards were enough to get him noticed for All-American honors.

DuPree was the last tight end to lead Michigan State University in receiving, doing it in each of his last 2 seasons.

He also had to take over for the recently retired and future hall of famer Mike Ditka, who gave him his jersey number 89.

He set a franchise record for tight ends with 3 touchdowns catches in a single game against the St. Louis Cardinals.

He assisted his team to a 27–10 victory over the Denver Broncos in Super Bowl XII as the game's top receiver (four catches for 66 yards).

In the 1982 season, he helped block on Tony Dorsett's record 99-yard touchdown run against the Minnesota Vikings.

The durable DuPree never missed a game in his 11 seasons in the league and was part of the franchise's legacy of Pro Bowl tight ends that includes: Jim Doran, Dick Bielski, Lee Folkins, Mike Ditka, Jay Saldi, Doug Cosbie, Jay Novacek and Jason Witten.