Rose Mary Woods, 87, the Nixon White House secretary whose improbable stretch was supposed to account for part of an 18 1/2-minute gap in a crucial Watergate tape, died Jan. 22 at a nursing home in Alliance, Ohio, where she lived. No cause of death was reported.

Miss Woods, the president’s private secretary, in 1973 was transcribing secretly recorded audiotapes of Oval Office conversations. She was working on a June 20, 1972, tape of a conversation between Nixon and his chief of staff, H.R. Haldeman, that might have shed light on whether Nixon knew about the Watergate break-in three days earlier. While she was performing her duties, she said, the phone rang. As she reached for it, she said she inadvertently struck the erase key on the tape recorder and kept her foot on the machine’s pedal, forwarding the tape.

A photograph taken of Miss Woods re-creating the event, nearly sprawling to do both simultaneously, made her gesture look like a gymnastic feat. Some wags, according to a Washington Post article at the time, dubbed it “the Rose Mary Stretch.”

Miss Woods testified to a federal grand jury in 1974 that she might have caused a four- or five-minute gap in the tape, but no more. Subsequent investigations concluded that there were five to nine separate erasures, but no one has ever determined what was erased. She had complained earlier to the grand jury that some of the tapes were of such bad quality that she doubted that exact transcripts could ever be made.

Miss Woods moved back to northeastern Ohio after leaving the federal government in 1976 and rarely spoke to the media. She was fiercely loyal to Nixon through his checkered political career and was with the family when the disgraced president prepared to leave the White House for the last time.

She had worked for Nixon since 1951 and was so close to the family that Tricia and Julie Nixon called her “Aunt Rose,” and she swapped clothes with first lady Pat Nixon. Nixon wrote in his memoirs that he asked his secretary to tell his wife and daughters that he planned to resign Aug. 9, 1974.

But she was far more than a family friend. Long before Haldeman and domestic aide John Ehrlichman joined the presidential campaign, Miss Woods was Nixon’s gatekeeper. Reporters said she controlled who could see her boss -- and punished those she deemed critical.

“Rose would die for [Nixon],” Beatrice Lucille Miller, her first boss, told The Washington Post in 1974. “Rose would just lay down her life and die for him.”

She remained loyal even after Nixon left office, keeping a sort of shrine to him in his hideaway office in the Executive Office Building until the Ford administration made her vacate it, according to an item in McCall’s magazine in 1975. “Rose left his half-smoked cigar in the ashtray, his glasses on his desk and his wastebasket half-filled,” the article said.

Miss Woods was born in Sebring, Ohio, and grew up in a Democratic household. After high school, she went to work at Royal China Inc., a pottery company in her home town. The man she planned to marry died before the wedding, and she moved to Washington in 1943, working in a variety of federal offices until she met Nixon while she was a secretary to the Select House Committee on Foreign Aid. Reportedly impressed by his neatness and the precision of his expense accounts, she accepted his job offer in 1951. Miss Woods remained his secretary for the rest of Nixon’s political career.

In a twist, Miss Woods, who became increasingly known during the investigation of the 1972 break-in at Democratic National Committee headquarters at the Watergate, was herself the victim of an earlier Watergate burglary.

Like a number of administration officials, she lived at one of the apartment houses in the complex. In 1969, after returning from an official overseas trip, she reported that jewelry valued at more than $5,000 had been taken from her apartment.

She was named one of the “75 Most Important Women in the United States” by Ladies Home Journal in January 1971, a decade after the Los Angeles Times named her its “Woman of the Year,” the first time the title was conferred on a secretary. The erasure landed her on the Dec. 10, 1973, cover of Time magazine.

In his autobiographical book, “Six Crises” (1962), Nixon said Miss Woods had “that rare and unique characteristic that marks the difference between a good secretary and great one -- she is always at her best when the pressures are greatest.”

She fought with Haldeman, who tried to limit her access to Nixon. Jonathan Aitkin, a Nixon biographer, told the Associated Press that one of the reasons the president and his secretary had such a long-lasting relationship was that their characters were similar.

“She was intelligent, literate, clamlike in her discretion,” he said.