Bourque finished his career with the Colorado Avalanche, with whom he won his only Stanley Cup championship in his final NHL game.

Halfway through his rookie season, head coach and general manager (GM) Michel Bergeron traded Bourque to Sorel for high-scoring Benoît Gosselin.

[6] Bourque made an immediate impact in Boston during his rookie season of 1979–80, scoring a goal in his first game while facing the Winnipeg Jets.

Bourque proved a solid force for Boston for 21 seasons (1979–2000), famous for combining offensive prowess at a level that few defencemen in league history had ever achieved—he was a perennial shot accuracy champion at All-Star Games—and near-unparalleled defensive excellence.

In the playoffs, Bourque led the team to the Stanley Cup Finals against the Edmonton Oilers in both 1988 and 1990, where the Bruins lost in both series.

Despite a nucleus of young talent and high expectations for 1999–2000, injuries caused the Bruins to plummet to the bottom of their division, and they went on track to miss the playoffs.

[13][14][15] With his career nearing an end and the team going in the wrong direction, Bourque requested a trade from the fading Bruins so he would have a chance to win the Stanley Cup.

He led all Colorado defencemen in scoring and formed a solid defensive pairing with Adam Foote and Rob Blake, the latter of whom the Avs received from the Los Angeles Kings in a trade.

Bourque was named to the post-season First All-Star team, finishing as runner-up to the Detroit Red Wings' Nicklas Lidström for the Norris Trophy.

The Avalanche advanced all the way to the Stanley Cup Finals, where Bourque scored the game-winning goal in Game 3 against the New Jersey Devils.

During the post-game presentation that followed the Avalanche's victory in the decisive seventh game, team captain Joe Sakic broke with tradition and gave the Cup to Bourque so he could skate with it first.

During the 2000–01 season, which would be the last for both players, Bourque surpassed Paul Coffey (who had just been acquired by the Bruins) to become the all-time leader in goals, assists and points for a defenceman at any senior professional level.

Bourque, thus, would be the last Bruin to wear number 7 and was permitted to do so as long as he desired to even after Esposito's retirement ceremony, which was scheduled for December 3 of that year.

Christopher played for the Hershey Bears of the American Hockey League (AHL) in the 2007 season and made his NHL debut for the Capitals in 2007.

[23] His younger son, Ryan, was a third-round draft choice of the New York Rangers in 2009, and was a member of the USA's 2010 gold-medal, World Junior Championship team, earning three assists during the tournament.

He won the Norris Trophy as the top defenceman in the league five times, fourth all-time after Bobby Orr, Doug Harvey and Nicklas Lidström.