Biden's brief remarks to the crowd in Shanksville were a contrast to the events at the World Trade Center site in New York, where politicians were not invited.
Gordon Felt, whose brother Edward was one of the Flight 93 passengers, said it was important for Biden and Salazar to attend because it's symbolic of the government's — and the American people's — view of the seriousness of the anniversary.
"I think that we're always concerned that Sept. 11 not be used for political purposes and in listening to all the remarks made here I think, once again, we realize this is apolitical," he said.
"This is something that since Sept. 11, 2001, that has united Americans. And I think as we look back in our memories, we remain united."
About 150 family members and invited guests were joined by hundreds of other attendees who began arriving after dawn, some from the rural community now inextricably tied to the events of the day and others making longer trips to pay their respects.
"Every 9/11 I come out to one of the sites," said Robert Hamel, 55, of El Segundo, Calif., wearing a black shirt with the image of the World Trade Center towers on it. Hamel spent the 10th anniversary last year at the New York City ceremony and plans to visit the Pentagon for next year's anniversary.
Don Hillegass, 63, last attended the anniversary ceremony two years ago. The crash site is about 15 miles from his home in the tiny hamlet of Manns Choice.
"It was a situation that happened close to us and is near and dear to the hearts of those in the surrounding area as well as the rest of the country," Hillegass said.
His neighbor, Thomas Fair, 53, was milking cows on his farm when he saw the smoke rising from the wreckage over a nearby hillside.
"I still wonder how someone could be so hateful and do that to someone else," Hillegass said. "It was kind of an eerie feeling that day."