Tony Sarsland, longtime Elk River High School boys’ hockey coach whose tumultuous reign included a state title, resigned Friday effective immediately amid a school district investigation.

The investigation means that Sarsland is on paid administrative leave from his duties as social studies teacher at VandenBerge Middle School pending what investigators learn, said district spokesman Casey Mahon.

Mahon would say only that Sarsland’s resignation was for “personal reasons.”

It came the day school staff interviewed up to 20 hockey players as part of an investigation that began Monday, Mahon said. He declined to elaborate on what precipitated the inquiry beyond saying the district felt an obligation to follow up on “some issues’’ that had come forward.

Sarsland did not return a telephone message at his home seeking comment.

Junior varsity coach Ben Gustafson was named interim coach to finish the season. The team’s next game is Saturday at home against Maple Grove.

In the past 15 seasons, the Elks have earned six trips to the state tournament -- winning it all in 2001 -- and claimed 12 conference championships.

But in Sarsland's nearly three decades at Elk River, the program has been under the microscope for everything from the coach's ability to control his anger, to the players' rough style of play to accusations of recruiting.

During a 1998 game, Sarsland threatened to break the nose and jaw of player Joe Bailey, an off-the-handle move that got him suspended for four games and nearly cost him his job.

To keep his job, Sarsland had to work with a sports psychologist and attend anger management sessions.

Two assistant coaches resigned after a political battle erupted in Elk River during Sarsland's suspension.

Three transfers from nearby Buffalo played on Elk River's state title team. In 2003-04, his team had transfers from Park of Cottage Grove, Andover and St. Michael-Albertville.

In a 2004 interview with the Star Tribune, Sarsland said, “I have a lot of critics out there, I understand that. All I ask is that they walk a few miles in my shoes.’’

A handful of NHL players have come out of Elk River under Sarsland’s guidance, most notably Paul Martin.

Sarsland played hockey and got his degree at St. Cloud State University before starting his teaching and coaching career (assistant in football and hockey) in 1970 at Hallock High School in northwestern Minnesota.

Stops at Columbia Heights and Beloit (Wis.) preceded his landing a job teaching and coaching hockey at Elk River in 1985.

Paul Walsh • 612-673-4482

Staff writers Paul Levy and Paul Klauda also contributed to this report.