Ms. Chenery reacts to Secretariat’s victory at the Belmont Stakes in 1973. (Jack Kanthal/AP)

“I really believe they are noble,” Penny Chenery once said of horses, the animals that commanded her love for nearly all her life. Perhaps the most noble of them all was Secretariat, the chestnut thoroughbred she owned and bred, who in 1973 captured the nation’s imagination when he won the Triple Crown.

Ms. Chenery, a figure­head of horse racing and one of the few women of her generation to vault to the front ranks of the sport, died Sept. 16 at her home in Boulder, Colo. She was 95. The cause was complications from a stroke, said a family spokesman and business associate, Leonard Lusky.

The daughter of a noted horse breeder, Ms. Chenery learned to ride as a girl and adored horses for their grace and athleticism. But she was largely unschooled in racing until the late 1960s, when it fell to her and her siblings to carry on their ailing father’s farm, called Meadow Stable, in Doswell, Va.

As Christopher Chenery succumbed to Alzheimer’s disease, his children divided responsibilities at the Meadow, as the farm was called, with Ms. Chenery overseeing the horses. Her father, a utilities executive, “was a self-made man who had passed on the fruits of his labor and his standards to his children,” she once told the New York Times, “and I didn’t think we ought to destroy them, and certainly not while he was still alive.”

Ms. Chenery, who was married at the time and used the name Penny Tweedy, commuted from her home in Colorado and later New York to the Virginia farm. Describing herself as “miscast as a wife and mother,” she found fulfillment in learning her father’s avocation.

Ms. Chenery signs autographs in Lexington, Ky., in 2004. (Mark Cornelison/Lexington Herald-Leader via AP)

A turning point came when she lost a coin toss to Ogden Phipps of Wheatley Stable to decide who would get which foals sired by Bold Ruler, a Phipps stallion, and born to mares from the Meadow.

Ms. Chenery lost the toss — a relief, she said, because she would not have known which horse to choose — and got the horse born March 30, 1970, to a mare named Somethingroyal. A secretary to Ms. Chenery’s father suggested he be called Secretariat.

Ms. Chenery once confessed to the Herald-Leader of Lexington, Ky., that she initially thought Secretariat, with his three white socks and distinctive white markings on his forehead, “was too pretty to be any good.”

“Handsome is as handsome does,” she said.

She initially placed greater hopes on another Meadow Stable racehorse, Riva Ridge, who won the Kentucky Derby and the Belmont Stakes in 1972. But Secretariat would prove an even greater sensation the following year, winning the Kentucky Derby, the Preakness and then, in the ultimate coup, the Belmont Stakes by 31 lengths.

Not since Citation in 1948 had a horse won the Triple Crown. And perhaps not since Seabiscuit, the champion racehorse who buoyed spirits during the Depression, did the nation rally so enthusiastically around a horse.

“The country was in a blue mood,” Ms. Chenery said years later. “It was the time of Watergate and the Nixon scandals, and people wanted something to make them feel good. This red horse with the blue-and-white blinkers and silks seemed to epitomize an American hero.”

Ms. Chenery confessed that Secretariat had buoyed her spirits as well. When she was in her early 90s, she confessed that, amid a failing marriage, she had an affair with Lucien Laurin, Secretariat’s trainer — a detail omitted from news accounts in the more private era of the 1970s.

“The experience of having Secretariat rescued me,” she said.

Helen Bates Chenery was born in New Rochelle, N.Y., on Jan. 27, 1922. She graduated in 1939 from the private Madeira School in McLean, Va., and in 1943 from Smith College in Northampton, Mass., before serving with the Red Cross in Europe during World War II.

She was studying business at Columbia University when she left the school to marry Tweedy. That marriage, as well as a subsequent one, to Lennart Ringquist, ended in divorce.

Survivors include four children from her first marriage, Sarah Manning of Albuquerque, Kate Tweedy and Chris Tweedy, both of Denver, and John Tweedy of Boulder; a stepson, Jon Ringquist of Los Angeles; and six grandchildren.

Ms. Chenery’s father died in 1973, before Secretariat’s Triple Crown victory. The horse was soon syndicated for $6.08 million, a record at the time.

She shared credit for Secretariat’s success with Laurin, who died in 2000; Eddie Sweat, the horse’s groom, or caretaker, who died in 1998; and Secretariat’s jockey, Ron Turcotte, who was left a paraplegic by a riding accident in 1978.

Secretariat died in 1989. A Disney film based on his story, “Secretariat” (2010), with Diane Lane playing Ms. Chenery, helped secure his memory among younger generations.

Ms. Chenery revealed her affair with Laurin in a 2013 documentary film directed by her son John Tweedy, “Penny & Red: The Story of Secretariat’s Owner.” She wished to dispel the sugarcoated Disney version of her story, she said, as well as the popular notion that she had a magical relationship with her horse. Her rapport with Secretariat was instead one of “mutual respect,” she said.

Long after selling Meadow Stable in 1979, Ms. Chenery remained a revered presence in horse racing. She was among the first women admitted to the Jockey Club. She did not make much of her distinction as a woman in the male-dominated sport. “I did all the things I did out of instinct,” she told the Atlantic in 2012. “I was not trying to be a role model.”

There was one privilege long denied to her: permission to enter the breeding shed. When her farm manager finally agreed to admit her along with the male staff, she realized, she joked to the Times, that she “hadn’t been missing all that much.”