Calder scored at 3:20 of overtime Tuesday night to give the Blackhawks a 3-2 win over the Blues as two of the NHL's worst teams concluded their 2005-06 schedules.
Calder netted the winner for the second straight game, beating Jason Bacashihua from right wing after his pass attempt to Brent Seabrook was blocked.
"I tried faking a shot, then sliding it over," Calder said. "It kind of hit (defenseman Christian Backman's) foot and bounced up. I knew the goalie wasn't in net and I got as good a shot on net as I could."
Radim Vrbata and Dustin Byfuglien scored for the Blackhawks, who finished the season with two straight wins, but just three in their last 10.
"It's been a long time since we won two games in a row and it's a huge bonus for a lot of guys in here," Calder said. "It's a losing season, but we have to take as many positives as we can out of it."
Timofei Shishkanov and Scott Young scored for St. Louis, which won just one of its last 19 games and finished with the NHL's worst record for the first time since joining the league in 1967-68.
The Blues finished with 57 points for the NHL's lowest total this season. Their point total was their lowest since 1978-79 and third worst in franchise history. St. Louis also missed the playoffs for the first time since 1979. The Blues had qualified for 25 straight seasons, the NHL's longest active streak.
"The season we've had, no one is proud of," St. Louis coach Mike Kitchen said. "I know Chicago's not proud of their season and we're certainly not proud of our season."
"If just doesn't feel like it's over yet. It's been such a difficult season, I don't know when it's going to sink in."
The Blackhawks missed the playoffs for the seventh times in eight seasons. Their total of 65 points was second lowest in the Western Conference and third worst in the league.
First-year Chicago coach Trent Yawney hopes to change that trend, possibly beginning next season.
"I hope they (Blackhawks players) just remember the empty feeling," Yawney said. "The fun season starts on Friday. Some of the guys, it's their first time not in the postseason, in some cases, since bantam hockey."
Chicago's Nikolai Khabibulin made 30 saves. Bacashihua blocked 49 shots.
"I'm sure we're a little sad about it," Bacashihua said. "I know I am. I've enjoyed my time here, but it's been a long year for the boys."
Shishkanov opened the scoring with 8:00 left in the first period. He picked up a loose pick in the Chicago zone and outsprinted Patrick Sharp to the net.
Vrbata tied it 1-1 2:24 later. He skated from behind the St. Louis net and slipped a backhander just inside the right post.
Young gave St. Louis a 2-1 lead at 4:57 of the second, beating Khabibulin with a screened wrist shot from just inside the blue line.
Byfluglien knotted it 2-all with 7:24 remaining in the second, converting a rebound of Milan Bartovic's shot from right wing.
The Blues are assured of the best odds -- 25 percent -- of getting the top pick in the NHL's draft lottery on Thursday. ... St. Louis C Dean McAmmmond was a healthy scratch. ... Seven Chicago players -- Matt Keith, Milan Bartovic, Michal Barinka, Danny Richmond, Mark Cullen, Dustin Byfuglien and Brandon Bochenski -- will be sent to Norfolk of the AHL on Wednesday to join the Blackhawks' farm team for the playoffs.