Eric Parsons / Star staff John Hall gets a hug from his daughter, Tiffany, after stopping for lunch on the first leg of his "Bike Ride Around America" on Tuesday at Rincon Beach.

John Hall is putting the pedal to prevention.

The 62-year-old emergency room doctor from Alaska set off Tuesday from a Lompoc cemetery on a whirlwind, four-month bicycle tour around the perimeter of the United States.

His cause: cancer prevention.

"If one woman gets a mammogram because of this ride, then it will be worth it," Hall said on the eve of his trip, which brought him to Ventura County on Tuesday.

Hall knows all too well the importance of detecting breast cancer early. Tuesday's departure coincided with the anniversary of his wife's breast cancer diagnosis.

Jane Hall had surgery, chemotherapy and radiation and survived to inspire her husband to begin the bicycle journey. She'll be his crew and companion, as she has been for 38 years, driving a support vehicle over the more than 12,000-mile route over the next 120 days.

"This is our cancer-free journey together," said John Hall, who three years ago covered 2,300 miles in 23 days from Vancouver, Canada, to Anchorage, where he lives.

As a seasoned doctor, Hall was no stranger to cancer. But before the disease hit home, he often found himself overwhelmed with pity and at a loss for words in front of his patients.

"I never felt uncomfortable in their presence," he said. "I felt sorry for them. But now I am able to radiate hope rather than pity. Because that is what they want to see — hope — in your eyes."

Early detection tests for breast cancer can save thousands of lives each year by getting women treatment before the cancer spreads, he said.

Following a coastal route, Hall reached the Ventura County line by mid-Tuesday. He made a wrong turn outside Montecito that cost him a dozen extra miles, but otherwise it was a good first day. The couple planned to spend the night in Oxnard, departing this morning for Newport Beach.

Hall has a Ventura County connection: He attended St. John's Seminary in Camarillo in the 1960s, before leaving the priesthood for medicine, he said. The second oldest of 10 siblings, Hall studied at UC Santa Barbara and later at UCLA's medical school.

He expects his and his wife's prevention pilgrimage will cost about $25,000, which the couple will pay for.

As a result, "every penny" people donate will benefit the two charities he's riding for: the Lance Armstrong Foundation and the Susan Butcher Family Center in Anchorage.

Armstrong, a cancer survivor, is a seven-time winner of the Tour de France. Butcher, who died from leukemia in 2006, was a champion dog musher, who won the grueling Iditarod sled race in Alaska four times.

The Butcher center is a special, supportive place for children to go while a parent or sibling is being treated for cancer — the leading cause of death in Alaska, he said.

In preparation for his ride, Hall launched a Web site, http://www.bikeridearoundamerica.org, that details his route and ways to give. He plans to update the site with blog entries along the way, he said.

His daughter, Tiffany, one of the couple's four children, was among a small group that cheered Hall as he departed early Tuesday from the ceremony in Lompoc, where his mother, who died 11 years ago from cancer, is buried alongside his father.

Her dad's heart and mind are strong, Tiffany said, but she worries about his aging legs and back.

No sweat, said dad, a former marathon runner who has been riding six days a week for months.

"Sometimes I feel best on the bike," he said. "And I'll only have to think about my wife and her courageous fight against her cancer if I need a little motivation."