VISTA -- The largest charter school in North County and Southwest Riverside County is undergoing a major administrative shakeup during what has become a tumultuous stretch in the school's six-year history.

Vista-based Eagles Peak Charter School serves roughly 4,000 students in three Southern California counties and, until recently, had been run by two separate school boards -- a "coastal" board responsible for learning centers in San Diego and Orange counties and an "inland" board responsible for the school's Riverside County operations.

The school began to split this fall into two separate agencies with the emergence of Eagles Peak Charter School Inland Empire, though the two programs continued to share the same management team.

On Wednesday, the coastal board voted to replace several of the organization's top administrators and appoint seven people to interim leadership positions at the nonprofit charter school, said William Wargo, a member of the Vista-based board.

The former administrators are expected to move to the Eagles Peak Charter School Inland Empire, he said.

The vote came less than two weeks after the board placed the school's executive director, Kathleen Hermsmeyer, on paid administrative leave and hired Arthur Townley to serve as interim director.

"The decisions we've made in the last few weeks have been made with a heavy heart," Wargo said Friday."The decisions we've made are decisions we've felt that we've had to make."

Board members can't discuss specifics on why the administrators are being replaced, he said.

In 2000, Eagles Peak opened in Vista with 260 students. By 2006, the school had learning centers in other communities including Chula Vista, Hemet, Indio, Jurupa, Riverside, San Juan Capistrano, Temecula, Tustin and Wildomar.

The charter school has been particularly popular with parents who home-school their children and are looking for an educational program that allows them to remain involved in the learning process.

Originally, all Eagles Peak learning centers were chartered through the Julian Union High School District, which still charters the San Diego and Orange county branches of the school.

Last year, the state required the school to start a separate charter, budget and school board in Riverside County, because more than half of the students the organization serves live there.

The Riverside County Office of Education agreed to charter the Inland Empire facilities in September 2005.

Trustees have said they are investigating accusations of mismanagement and misuse of public money at the school, but they haven't publicly discussed specific charges.

The two boards are in the process of meshing out all of the details of the split, including important questions about finance, facilities and administration, Wargo said.

"Part of the problem is that up until now, there's been one administration and two boards," he said. "From Sept. 1 to the present, everything was operationally being handled pretty much as if it was one school."

The board is trying to trying to keep the learning centers functioning without interruption while sorting out recent developments, Wargo said.

"The school still has to function," he said. "We can't just close down and wait a while."

The school board in Julian is closely watching the situation and will be reviewing the school's financial status, Superintendent Rich Alderson said this week.

Though the district is responsible for overseeing the charter school, it doesn't have any direct control over the governance of the campuses, he said.

"The board is very aware that there are a lot of children involved in this," he said. "They're going to do everything they can to support the families and children at Eagles Peak."

Most of the new administrators served under those being replaced or in the same department, Wargo said.

The new interim administrators appointed this week to serve the San Diego and Orange County school are Theresa Fisher, interim director of assessment; Mike Green, interim director of purchasing; Linda Nolte, interim director of instructional support; William Robbins, interim director of facilities; Chris Baughman, interim director of curriculum; Maria Kirkbride, interim senior director of home school; and Jill Porras, interim senior director of academy programs.

Staff writer Jennifer Kabbany contributed to this report. Contact staff writer Stacy Brandt at (760) 631-6622 or sbrandt@nctimes.com.