The removal of 27 children at a private facility for adopted children in Montana this week was the culmination of years of efforts to effectively regulate private youth treatment programs — and it "may just be the tip of the iceberg," the lawmaker who spearheaded the reform effort said Thursday.

The children were removed Tuesday from the Ranch for Kids in Rexford, in Lincoln County along the Canadian border, in response to what state officials called frequent and severe allegations of physical and psychological abuse. Some have already been reunited with their parents, state officials said.

The crackdown by the state Department of Public Health and Human Services came only three weeks after a new law to regulate facilities like Ranch for Kids went into effect July 1. At least 12 previous regulatory measures had failed until The Missoulian newspaper of Missoula published the results of a yearlong investigation in January detailing critical failures in oversight at some of the state's so-called alternative adolescent residences.

Among other shortfalls, the Missoulian investigation found that unlicensed counselors cared for children with serious disorders and that children were often isolated from their parents for months with no way to report abuses.

State Sen. Diane Sands, a Democrat from Missoula who led efforts to enact the law, told NBC News on Thursday that she hadn't expected the Health Department to move so quickly. The rules are still being written, she said, but "when the tip came in and the information was of such a serious nature, there was enough evidence to go directly to a judge."

"This was a case in which I am really proud of how swiftly and thoroughly they acted," she said.

Sands said more enforcement actions were likely elsewhere in the state.

"We've heard complaints from some of the other facilities that are way more horrible," she said. "This may just be the tip of the iceberg."

Ranch for Kids Project, a nonprofit organization founded in 2004, describes itself as a respite care program for at-risk adopted children and their families, particularly children suffering from fetal alcohol syndrome and reactive attachment disorder, which is a condition found in children who have been mistreated by previous caregivers.

The Health Department said tips and reports of "egregious abuse" at the ranch had been rising "in both frequency and severity in recent months," including allegations that:

Children were hit, kicked, body slammed and spit on by staff members.

Staff members inflicted "persistent psychological abuse" on children, including prolonged isolation.

Children were forced to go on 15- to 20-mile "disciplinary walks" on remote Forest Service roads in harsh conditions.

Food was withheld from children.

A nail gun was shot at a child.

"We don't allow people who are convicted felons who are in prison to be treated this way," Sand said Thursday.

Ranch for Kids didn't respond to email and telephone requests for comment. In an interview with NBC affiliate KECI of Missoula, William Sutley, the organization's executive director, denied the state's allegations.

"If I'm guilty, I should be in jail. If these things are true, you should put me in jail," Sutley said. "Here's the thing: Our passion is to help these kids heal from trauma, and now the state is saying that we are traumatizing these kids? Well, it's just not true."

The Missoulian, meanwhile, quoted Sutley as denying some of the allegations and saying others were blown out of proportion to discredit the facility. He acknowledged that children were sometimes sent on long walks as a form of discipline, but he said that never happened under improper conditions, the newspaper reported.

"This may just be the tip of the iceberg," says Montana state Sen. Diane Sands, a Democrat from Missoula, who led efforts to regulate alternative private youth residential facilities. Montana Legislature

For years, alternative adolescent residences were overseen by a board under the state Department of Labor and Industry, not the Health Department. The majority of the members of the Labor Department board were industry representatives; faith-based or religious programs were exempt from any regulation or licensing. That changed on July 1.

Many of the previously unregulated facilities are in the isolated, rural northwestern part of the state, far even from major highways, much less regulatory institutions.

"This area up there has a long history of these churches that are created," Sands said. "They change their name and are just a vehicle for all kinds of people to do all kinds of things."

In its publicity materials, Ranch for Kids describes itself as "based on Christian principles." In state registration and federal tax documents, it says it is an adjunct ministry of Epicenter International Missions Ministry, and in 2012, it argued that it was exempt from licensing regulations under the religious exception.

The following year, a state judge agreed with the Labor Department oversight board's contention that Ranch for Kids had falsely claimed religious affiliation to avoid state regulation, noting that Epicenter had no building, no congregation and no ordained clergy. The ranch then registered with the industry-dominated state board.

No contact information for Epicenter International was listed in publicly available state records.

The ranch's founder, Joyce Sterkel, retired several years ago and couldn't be reached for comment. In an interview in 2013 with The Christian Post, an evangelical news site, Sterkel called the dispute "another example of government interfering and hampering small business."

"We are an economic benefit to our community," she said at the time. "Our students provide community service here locally, and on a rotating basis we provide food and meals at our local soup kitchen."

In its federal tax filings, the ranch says it is "a spinoff of Global Adoption Services Inc. for the purpose of providing respite care services for special adoptees from foreign countries making transitions to the United States." Global Adoption Services is an organization accredited by the U.S. State Department to provide foreign adoption services.

Global Adoption Services told NBC News that it broke with Ranch for Kids years ago because the Montana group declined to adhere to State Department oversight requirements.

"We in Maryland had to make a clean and complete break from Montana and have had no contact with them since that time," the organization said.