The Mount Desert Island High School and Houlton High School girls basketball teams suffered potentially devastating losses this season when Sierra Tapley and Katie Condon were lost for the season because of knee injuries.

Prolific-scoring MDI point guard Tapley was a third team Bangor Daily News All-Maine selection last season and earned a full scholarship to play at the University of Maine. Forward-center Condon was a standout post player for Houlton who averaged over 10 points and eight rebounds per game.

However, neither team has lost a game since their stars went down, and they will be two of the favorites in the Class B North basketball tournament at the Cross Insurance Center in Bangor.

The B-C-D North tourney gets underway Friday in Bangor, and the A North tourney starts at the Augusta Civic Center.

“I think Houlton has the best team, especially since MDI is without Tapley,” said Jeff Hudson, coach of defending regional B champ Presque Isle. “But MDI has played real well and has won a lot of close games.”

“MDI has Kelsey Shaw and Houlton has Kolleen Bouchard, and they can each take a game over by themselves,” added Hudson.

“It would not surprise me if a couple higher seeds got upset early in the tournament,” said Houlton coach Shawn Graham, whose Shiretowners are the defending state Class C titlist but have returned to Class B.

“Every game could go either way,” said Brent Barker, coach of the 17-1 MDI Trojans.

Top seed Houlton, 17-1, has four players averaging in double figures led by Bouchard’s 20.6 points, Natalie Hill’s 11.9, Aspen Flewelling’s 11.8 and Rylee Warman’s 10. Bouchard also is averaging nine rebounds and four blocked shots.

“I can’t say enough about Flewelling. She is as good a 3-point shooter as I’ve had,” Graham said.

Shaw, a 1,000-point scorer, has averaged 19 points and 12 rebounds, and senior Keely McConomy has been good for nine points and eight rebounds. Guards Mariah Hamor, Abbe Miller and Maya Watras have been key contributors, and the Trojans have played excellent defense.

Sophomore Emily Wheaton (15 ppg) has led 15-3 Presque Isle, and 3-point specialist Emily Lagerstrom has scored nine per game. Top-notch defender Olivia Hudson has been scoring lately to help the Wildcats.

Heather Kervin has averaged 16 points per game for 15-3 Winslow, and Delaney Wood has been an important shutdown defender and leader while also averaging seven points per game. The running Raiders of coach Lindsey Withee also have featured freshmen Weslee Littlefield and Paige Trask and sophomore Sarah Guimond.

Young and athletic John Bapst of Bangor and surging Hermon are dangerous lower seeds.

In Class C, 17-1 Fort Fairfield and 14-4 Dexter are the top two seeds, but Fort Fairfield coach Larry Gardner and Dexter’s Jody Grant feel the tourney is wide open.

“Several teams could win it,” said Grant.

Taylor Churchill has averaged 16 points per game for Fort Fairfield, and point guard Chelsey Pelkey has averaged 10 points and seven assists and has had a number of triple-doubles. Kayla Giberson and Teresa Maynard also have been standouts. All four are seniors.

“All the kids have played pretty well,” said Gardner.

Six-foot-one center Megan Peach (15 ppg, 11 rpg) and 5-10 forward Katie Batron (10 ppg, 8 rpg) have given the Tigers a nice one-two punch, and Abby Webber and Cidney Pratt have provided quality guard play.

“We’ve played a tough schedule, so we’re battle-tested,” Grant said.

The 15-2 Narraguagus Knights of Harrington have been led by 1,000-point scorer Kelli Kennedy (23 ppg, 12 rpg), Emily Reynolds (7 ppg, 8 rpg) and Madison Leighton (8 ppg, 5 apg, 5 steals per game); 14-4 Penobscot Valley of Howland is a legitimate contender behind 1,000-point scorer Sami Ireland, and Amy Hallett and 15-4 Schenck of East Millinocket is another threat behind Kayla Falone and Chantel Lane.

In Class D, Washburn is the defending five-time state champ but lost 2,000-point scorer Mackenzie Worcester and fellow standout Joan Overman to Bangor’s Husson University.

However, coach Diana Trams’ Beavers still strung together a 14-4 season good for the second seed behind the surprising Southern Aroostook Warriors from Dyer Brook, whose four freshmen and four eighth-graders posted a 13-5 campaign after a 3-15 showing last year.

Every team in Class D lost at least four games.

“We aren’t a typical No. 1 team. But we’re happy with where we are. We played some tough competition down the stretch,” said Southern Aroostook coach Cliff Urquhart, whose Warriors have been led by 5-9 freshman point guard Kassidy Mathers (15 ppg), freshman guard-forward and rebound leader Kylie Vining (9 ppg, 10 rpg) and 5-8 eighth-grade center Sydney Brewer (13 ppg, 9 rpg).

Urquhart said there is no shortage of contenders.

“Central Aroostook struggled with injuries early but is getting everybody back. Karli Levesque is a 1,000-point scorer, and they have two excellent guards in Kelsey Dominique and Molly Anthony,” said Urquhart.

“ Washburn is an athletic team with al lot of experience, and going up against Worcester and Overman in practice every day has to make you better,” he added. “Katahdin is the most dangerous team in the tournament. Molly Cunningham is real good inside; she blocks a lot of shots. They have a ton of size, and they have athletic guards in Courtney Stevens and Georgia Landry.”

Seven of Katahdin’s nine losses came to the top seven Class C schools.

Trams said long playoff runs culminating in state championships has given her players the equivalence of “another full season of experience.”

Senior guard Emmy Churchill leads the team in points (14 ppg) and rebounds (10 rpg), and Laine Mette (12 ppg) and Grace Braley (12 ppg) have been the other catalysts.

Holly Preston and Cierra Seeley have been 12-6 Shead of Eastport’s driving force, and 1,000-point scorer Tate Dolley has been 10-8 Machias’ leader.

Unlike the other classes, there is a clear-cut favorite in Class A North in defending state champ Lawrence of Fairfield, 18-0 and winner of 39 of its last 40 games.

Lawrence’s average margin of victory is 28.3 points.

Lawrence has two 1,000-point scorers in 2014-15 Maine Gatorade Player of the Year and first team BDN All-Maine selection Nia Irving (25 ppg, 20 rpg) along with sharpshooting guard Dominique Lewis (15 ppg, 6 apg).

Boston University-bound Irving also has over 1,000 career rebounds.

There is an impressive supporting cast led by Morgan Boudreau.

Messalonskee of Oakland, 15-3, has been led by Sophia Holmes (20 ppg) and Taylor Easler and could be the primary threat to Lawrence, but the Eagles lost each of its two games to coach John Donato’s Bulldogs by 24 points.

Gardiner has had an impressive 14-4 campaign behind Mary Toman and Lauren Chadwick, and 13-5 Nokomis of Newport features Sidney Moore, Olivia Brown and Chelsea Crockett.