WASHINGTON — Sexual harassment, bullying and other misconduct are rampant among employees at national parks across the country, including at iconic sites such as Yosemite, Yellowstone and the Grand Canyon, a congressional committee was told Thursday.

At Yosemite, at least 18 employees have come forward with allegations of harassment or other misconduct so severe that a recent report labeled working conditions at the park “toxic.”

At Yellowstone, officials are investigating complaints of sexual exploitation, intimidation and retaliation.

The complaints follow a report by the Interior Department’s inspector general that found male employees at the Grand Canyon preyed on female colleagues, demanded sex and retaliated against women who refused.

In a separate case, the park service has temporarily reassigned the superintendent of a Florida park where female employees long complained of sexual harassment.

“There seems to be some patterns here that are just not anything we should come close to tolerating,” said Rep. Jason Chaffetz, R-Utah, chairman of House Oversight and Government Reform Committee.

Michael Reynolds, deputy director of operations for the National Park Service, acknowledged problems at many of the 413 park sites.

Widely reported problems at the Grand Canyon and the Canaveral National Seashore in Florida “were more than a wake-up call,” Reynolds told lawmakers. “They presented us with … evidence that … we must extend the same commitment to the employees of the National Park Service as we make to the protection of our nation’s most extraordinary places.”

Asked if he agreed the agency has a problem with harassment and hostile work environments, Reynolds said yes.

Kelly Martin, Yosemite’s chief of fire and aviation management, told lawmakers that she has been sexually harassed throughout her 32-year career.

Early in her career, a Grand Canyon park ranger stood outside her bathroom window and watched her shower, Martin said. After she reported the incident, he apologized and no further action was taken. The ranger was repeatedly caught engaging in voyeuristic behavior, all the while receiving promotions around the agency.

At Yosemite, dozens of people, mostly women, “are being bullied, belittled, disenfranchised and marginalized from their roles as dedicated professionals,” Martin said.