A day after being fired as chief of the U.S. Park Police, Teresa C. Chambers said yesterday that she was surprised by the timing of the action but vowed to continue with her vigorous public campaign to reclaim her position with the Department of the Interior.

"The fight has really just begun," she said. "My focus is on going back to my job."

Chambers, 47, who had been suspended with pay since December for publicly stating that her police force was overworked and understaffed, spoke between fielding calls from well-wishers at her suburban Maryland home.

She said that for the past seven months, she remained hopeful that someone from the Interior Department would come to her defense, "never believing until [Friday] that that wouldn't happen."

She acknowledged that losing her $135,000-a-year job was financially significant but said that in every other way, the firing has given momentum to her efforts.

She has turned her case into a broader cause about the importance of public disclosure.

"It's not about me. It's not about the U.S. Park Police. It's about the American citizens having a right to know what's going on," she said.

The Interior Department placed Chambers on leave after she publicly stated that her 620-member force, which polices federal parkland and national monuments, needed more than twice as many officers and a significant budget increase.

The National Park Service, an arm of Interior, accused Chambers of endangering security and said she violated rules against the improper lobbying of Congress.

In a statement issued Friday, Interior officials said they weighed a variety of factors before deciding to fire Chambers, including "the nature and seriousness of the offense," her work record and job performance and the potential for "rehabilitation."

Several telephone attempts to reach an Interior Department spokesman at the office and at home were unsuccessful yesterday.

Chambers was a neophyte to the federal government in February 2002 when she became the first woman to head the Park Police in its 213-year history.

She worked in law enforcement for 27 years, including as police chief in Durham, N.C., and as a commander in Prince George's County.

After her suspension last year, Chambers's husband created a Web site, www.honestchief.com, that has received 84,000 hits, Chambers said. Anonymous comments posted to the Web site yesterday came from across the country, and most demanded that the chief get her job back.

Chambers said she personally received more than 1,200 e-mails about her firing.

Tomorrow, Chambers will talk with an administrative law judge in a previously scheduled conference call about her complaint to the Merit Systems Protection Board.

Chambers filed a request with the judge, Elizabeth B. Bogle, on Friday seeking immediate reinstatement. She was fired hours after filing those legal papers.

Staff researcher Meg Smith contributed to this report.

Teresa C. Chambers was suspended after discussing her funding concerns.