La PINE, Ore. -

La Pine High School’s cheerleading coach has been arrested on charges of sex abuse and furnishing alcohol to a minor, alleging she engaged in inappropriate behavior with a 17-year-old male student, Deschutes County sheriff’s deputies said Thursday. School officials said she resigned from her position after the investigation began.

A staff member at the school, a “mandatory reporter” of abuse under state law, notified the sheriff’s office on March 21 of rumors alleging that Nicole Mickelson, 30, of La Pine, had been involved inappropriately with a 17-year-old male student, said sheriff’s Lt. Deron McMaster.

A responding deputy initiated the investigation, which then was referred to a sheriff’s office school resource deputy.

McMaster told NewsChannel 21 Mickelson was partying with four students in early March, including the 17-year-old male she had sex with.

A week ago, when the investigation concluded, Mickelson was arrested on four counts of second-degree sexual abuse, four counts of sexual misconduct and three counts of furnishing liquor to a minor. Mickelson previously had been cited on one count of furnishing liquor to a minor, McMaster said.

Mickelson was booked into the county jail in Bend and released after posting 10 percent of her $30,000 bail. She’s due to make an initial court appearance on Thursday, May 2nd at 1:30 p.m.

School officials said Mickelson was hired to coach at the school in the fall of 2011, but is no longer a school employee.

"The employee resigned prior to charges being brought, but their investigation was pending, had begun, and the resignation followed shortly after," said Bend-La Pine Schools Assistant Superintendent Jay Mathisen.

Students said she was popular with the high schoolers.

"She was very nice," said a friend of the victim who wanted to remain anonymous. "She definitely got along with everybody, kind of had that high school mentality, so she kind of fit in -- and I never expected that."

Police say it was not an on-going relationship, and the victim's friend told NewsChannel 21 that the sex only happened once.

"I think there was ongoing conversations and everything afterward, but I think, to my knowledge, it was only that one time at the party," he said.

Residents of La Pine say the news is sickening.

"You put a person in charge that the kids have respect for and then take advantage of the situation, it's terrible," said La Pine resident Tim Jenning.

School officials said it was a staff member who reported the rumors that were swirling around the high school.

"It is something that we take very seriously, and our employees conduct complete annual training," Mathisen said.