St. Louis Blues rookie David Backes was a high school senior in Minneapolis when the NCAA Division I hockey championships came to the Twin Cities in 2002. All four schools brought their pep bands and legions of loyal supporters, creating a boisterous, fever-pitched environment. The play brimmed with passion and fire.

“I got to go,” Backes said, “and the atmosphere in the building was unbelievable.”

The semifinals and championship game, known as “the Frozen Four,” drew nearly 40,000 spectators to Excel Center in St. Paul. Minnesota beat Maine 4-3 in overtime for the title, and Backes was hooked.

The following August, he enrolled at Minnesota State-Mankato, choosing college over the major junior leagues in Canada that traditionally produced most of the NHL prospects.

Backes’ experience is not unusual anymore; college hockey has been on a steady rise. Some 59 schools field Division I teams (up from 40 in 1990), and nearly 25 percent of the current 900-plus NHL players came out of college hockey programs, according to figures compiled by the Elias Sports Bureau.

Former Blues star Red Berenson, Michigan’s coach since 1984, said college hockey “was a grass-roots sport when I came down here; now, it’s big-time. It’s been dramatic.”

Mike Zuke, who spent five of his eight NHL seasons with the Blues, traces the launch point to the 1980 Olympics, when a squad of college players upended the heavily favored Soviet Union en route to the gold medal.

Better players became interested in college hockey, which boosted the caliber of play, which kindled fan appeal, which got the attention of the media, which led to greater exposure, which stirred more interest.

A monster was created: The Frozen Four, which is televised nationally by ESPN, has been a sellout nine of the past 10 years (the exception was in 1999, when Anaheim, Calif., was the site), including this year’s tournament April 5-7 at Scottrade Center in St. Louis.

“It isn’t quite like when I played” at Denver in the early “70s, Blues executive Bruce Affleck said, laughing. Many Frozen Four attendees “have gone to the last eight, nine, 10 in a row,” he said. “It’s their vacation time. It’s all the old college buddies, and it’s their annual trip. It’s become quite a tradition.”

For years, college hockey was a niche sport that produced only a handful of NHL prospects and lacked a fan base. When Zuke’s Michigan Tech squad whipped Minnesota 6-1 in the 1975 title game, 6,838 turned up at The Arena on Oakland Avenue, which seated about 20,000.

Professional coaches “didn’t know much about college hockey,” Zuke said. “Not until after that “80 year did they take college hockey as a really serious avenue for kids to become pros.”

In 1962, Berenson, a native of Regina, Saskatchewan, became the first player to go directly from college to the NHL. He had opted for Michigan even though the storied Montreal Canadiens drafted him.

“In those days the pros would say, “Well, you’ll never be a pro if you go to school.’ And there are still some people around that have that attitude; our big competition is still major-junior in Canada,” Berenson said. “But if I had a son who was destined to be a pro hockey player, I’d send him to college, no question.”

All three of Blues coach Andy Murray’s children chose college hockey. Oldest son Brady starred at North Dakota, daughter Sarah plays for Minnesota-Duluth, and youngest son Jordy, a high school junior, has committed to 2006 national champion Wisconsin.

“The coaching is better than it’s ever been at the college level,” Murray said. “I think college hockey is a great sport.”

Murray’s roster includes seven players who went the college route, including forward Lee Stempniak, who spent his four years at Dartmouth.

“I went there as a skinny 18-year-old who hadn’t touched a weight,” Stempniak said. “And you come out after four years, you’ve learned about your body and the strength and conditioning side of it. There are so many practices where there can be an emphasis on individual skill development, more so than just playing games. … I wouldn’t do it any other way.”

Several Division I schools are competing in sparkling new “” and expanded “” facilities. “I could name you 15 new rinks in the last 10 years,” Berenson said. “Some of them are just about an NHL-type building.”

NHL teams play 82 games and major-junior teams around 70; college schedules comprise 35 to 40 games. The result, said Robert Morris coach Derek Schooley, is a physical, fast-paced product that fans embrace.

“The energy that college hockey players play with is just phenomenal; they compete so hard,” said Schooley. “Every game is like the seventh game of the Stanley Cup. There’s so much emotion and so much passion.”

Attendance throughout each of the six D-I conferences is strong, the powerful WCHA, for example, drew 19,463 fans to its tournament final on Saturday night.

ESPN has televised the Frozen Four since 1980. This season, it televised 20 regular-season games and plans to show all 12 regional games on ESPNU.

“College hockey is a great game, and the Frozen Four is a huge event,” said Blues forward Jamal Mayers, a Western Michigan alum. “It’s unfortunate we’re going to be on the road. I’d like to catch those games.”