The college hockey conference that many in Minnesota love to hate will have three teams in the NCAA Frozen Four at Xcel Energy Center.

Ohio State and Michigan won regional championships on Sunday, joining fellow Big Ten Conference member Notre Dame, which earned its spot Saturday, in the national semifinals on April 5.

The team left to fend off the Big Ten trio will be Minnesota Duluth, which advanced Saturday night by beating Air Force in the West Regional final in Sioux Falls.

The semifinals of an all-West Frozen Four will feature Michigan facing Notre Dame, and Minnesota Duluth meeting Ohio State.

The semifinal winners will meet April 7 for the championship, and if the Bulldogs don't beat the Buckeyes, the final will be an all-Big Ten affair.

The Big Ten, in its fifth season as a hockey conference, has been less than popular in Minnesota because the league was formed by taking the Gophers and Wisconsin out the old WCHA, Michigan, Michigan State and Ohio State out of the now-defunct CCHA and adding newcomer Penn State. Out with those changes went the popular WCHA Final Five, which at times drew crowds of more than 19,000 to Xcel Energy Center.

Minnesota Duluth (23-16-3), which lost 3-2 to Denver in last year's NCAA final, will be the team trying to break through that Big Ten blockade. The Bulldogs earned their second consecutive Frozen Four berth by overwhelming Air Force early and holding on late for a 2-1 victory. The Bulldogs took a 2-0 lead on goals by Joey Anderson and Nick Wolff while outshooting the Falcons 14-0 in the first period. Air Force trimmed the lead to one goal on a power-play goal with 6:16 left in the third, but UMD held on during a flurry of late pressure by the Falcons.

The Bulldogs were the last at-large team to make the NCAA field, doing so when six conference title game results in their favor moved them ahead of the Gophers.

"The way we got in was a spark for our team," said UMD coach Scott Sandelin, whose team has played nine consecutive one-goal games in NCAA play, going 6-3 in that span. "It was dramatic, and our guys really appreciated the opportunity that they got."

The Bulldogs won their only national championship in 2011 in St. Paul, beating Michigan 3-2 in overtime. "It's exciting that it's in St. Paul," Sandelin said. "We had a good memory there last time."

Ohio State (26-9-5) throttled defending national champion Denver 5-1 to win the Midwest Regional in Allentown, Pa. The Buckeyes, the runners-up to Notre Dame in both the Big Ten regular season and conference tournament, have won six of their past seven games.

The Buckeyes, coached by St. Paul native Steve Rohlik, rely on goalie Sean Romeo, who had a 2.09 goals-against average and .925 save percentage entering the regional final, and the nation's best penalty kill (89.1 percent).

Michigan earned its 25th national semifinal spot — and third in all three Frozen Fours at the X — with a 6-3 victory over Boston University in the Northeast Regional final in Worcester, Mass.

The Wolverines (22-14-3) have won nine of their past 10 games and will try to add to their record total of nine NCAA championships.

Notre Dame (27-9-2) advanced to St. Paul with some late heroics from Minnesotans in the East Regional in Bridgeport, Conn. Senior defenseman Jordan Gross of Maple Grove scored 16:24 into overtime to beat Michigan Tech 4-3 in the semifinals, and junior forward Dylan Malmquist of Edina scored with 27 seconds left in the third period to beat Providence 2-1 in the final.