Sexual harassment and bullying among National Park Service employees at some of the nation's most iconic parks—including Yosemite, Yellowstone, and the Grand Canyon—is pervasive and has continued unabated for years, a congressional committee said this week.

At Yosemite alone, at least 18 employees described working conditions as “toxic,” said Rep. Jason Chaffetz (R-Utah), who chairs the House Oversight and Government Reform Committee.

Two whistleblowers—Kelly Martin, chief of fire and aviation management at Yosemite National Park and Brian Healy, the fisheries program manager at the Grand Canyon National Park—detailed several alleged offenses at both parks.

Martin, who began working for the Park Service 32 years ago, described three incidents that she said happened to her when she was in her twenties. One incident, she said, involved a park ranger spying on her through her bathroom window when she was working at the Grand Canyon. She reported him to her supervisor. The ranger was ordered to apologize to her, then continued to advance in his career until he retired as a deputy superintendent in 1987. Martin said she did not file an official complaint.

“I felt shame on how to proceed because I felt there would be backlash for reporting, and I did not want this to become public knowledge to other coworkers of mine,” Martin said in her prepared testimony. Years later, she said, she learned that other women had been stalked by the same ranger.

The second incident also occurred at the Grand Canyon. A male supervisor kept photographs of Martin above the sun visor in his government-issued vehicle. Then, one day when she was alone at her office, she said, he pushed her against a wall and tried to kiss her. She said the third incident involved another male supervisor who ran his fingers through her hair while she sat next to him on a couch at a work-sponsored meeting. When she reported the incident to a supervisor, he replied: “Well, it’s your word against his.”

Martin said she was confounded by the response and concluded that to stay in her job, she would have to figure out how to “navigate ubiquitous harassing and hostile work environments as a way of self-survival and preservation.”

She told the committee that even now, she had been reluctant to testify, out of fear of retaliation.

“It is a deep, conflicted and risky decision for me to come forward and speak up today,” Martin said.

Healy, the other whistleblower, told lawmakers that some employees implicated in harassment are still in their jobs, which has eroded morale and confidence in Park Service management.

The scandal began unfolding in public last January, just as the Park Service launched a yearlong celebration of its centennial year. The Interior Department’s Office of Inspector General released a report alleging sexual harassment by male boatmen at the Grand Canyon’s river district that had continued for almost 20 years. The report said that women employees were propositioned for sex and faced retaliation if they refused or reported incidents to supervisors.

In June, the inspector general released a report on sexual harassment at the Canaveral National Seashore on the Florida coast, east of Orlando. The report cited four investigations of that park since 2012. Among the findings were an offensive comment made by a male manager to a female subordinate that her dress so resembled a Creamsicle that he could “lick it up.”

Park Service executives vowed last spring to end harassment, declaring a “zero tolerance” position on sexual harassment. But at the September 22 hearing—in a rare show of bipartisan unity—Congressional committee members accused Park Service management of failing to take harassment seriously.

“When you have a fact pattern of someone spying on another person while they are taking a shower, you don’t need a policy change and you don’t need a new memo,” said Rep. Trey Gowdy (R-South Carolina). “You need handcuffs and a trip to the sex-offenders registry, that’s what you need.”

Michael Reynolds, the Park Service’s deputy director of operations, told the panel the agency is trying to change a culture. He described the allegations of abuse at the Grand Canyon and the Canaveral National Seashore as “a wake-up call” to act.

The Park Service has appointed a new superintendent for the Grand Canyon, Christine Lehnertz, and replaced the chief ranger at Canaveral, he said.