TULELAKE, Calif. — Under a cloud-filled sky, the Japanese-American pilgrims sat on folding chairs facing a vast, flat and dusty landscape whose monotony was broken only by two oddly shaped mountains that rose to the east and west. For the souls of the hundreds buried in a long-vanished cemetery here, a Buddhist minister offered prayers and rang a bell, though its invocation was almost lost as a propeller plane took off from a nearby airfield.


Nearly 400 Japanese-Americans journeyed from June 30 to July 3 to this remote corner of California, where 18,789 people of Japanese ancestry were incarcerated during World War II. The turnout was one of the highest ever for the four-day pilgrimage, which occurs every other year around the Fourth of July, organizers said. They surmise that as the number of the camp’s survivors dwindles, there is a growing urgency to understand — and reinterpret — what has been a hidden subchapter in America’s history.


Of the 10 internment camps in which about 120,000 Japanese-Americans were confined during the war, it was Tule Lake that held those branded “disloyal,” the ones who answered “no” to two critical questions in a loyalty test administered by the federal government.


After the end of the war, the no-noes, as they were known, not only struggled to find a place in mainstream society, but also were regarded with suspicion by other Japanese-Americans, whose pledge of undivided loyalty and search for larger acceptance could have been threatened by the no-noes.


For decades, the no-noes themselves never explained what lay behind their answers. Most, in fact, never spoke about Tule Lake at all.


“I came here because I want to know why my parents told me never to talk about Tule Lake,” said James Katsumi Nehira, 68, who was riding a bus on a tour here with his daughter, Cherilyn, 37. “They were ostracized and ashamed they were in Tule Lake. I never talked about it. I honored my dad’s wishes until he passed away.”


But in recent years, former detainees have begun speaking during the pilgrimages about why they, or more likely their parents, chose not to answer “yes.” Their stories, as they have filtered out of this small circle into the wider Japanese-American community, have added layers of complexity to the long-held view of the no-noes as simply disloyal troublemakers.


In early 1943, about a year after Japanese-Americans were rounded up into the camps, the American authorities, seeking Japanese language speakers in the military, distributed a loyalty questionnaire to all adults. Question No. 27 asked draft-age men whether they were willing to serve in the armed forces. No. 28 asked whether detainees would “swear unqualified allegiance to the United States” and “forswear any form of allegiance or obedience to the Japanese emperor, or any other foreign government.”


Anything except a simple “yes” to the two questions meant relocation to Tule Lake, which became the most heavily guarded of the camps. Army tanks were stationed here, reinforcing the security provided by 28 guard towers and a seven-foot-high barbed wire fence.


Osamu Hasegawa, 90, recalled that his parents answered “no” after a heated family debate. Because his parents were born in Japan — Japanese immigrants were not allowed to become American citizens until 1952 because of discriminatory immigration laws — they feared that forswearing allegiance to the country of their birth would render them stateless while Mr. Hasegawa and his American-born siblings remained in the United States.


After his parents answered “no,” Mr. Hasegawa became one of the nearly 6,000 Japanese-Americans at Tule Lake to renounce their American citizenship.


“They wanted to go back to Japan to keep the family together,” Mr. Hasegawa said.


Most of the family went to Japan. But his older brother Hiroshi, who had tried to persuade his parents to answer “yes,” remained, eventually joining the 442nd Regimental Combat Team, the Army’s famed Japanese-American unit.


Like most who went to Japan, Mr. Hasegawa and his family regained their citizenship, and they returned to the United States after 11 years. But relations between the brothers remained strained for decades.


“They reconciled only two years ago at the last pilgrimage here,” said Carol Hasegawa, the daughter of Hiroshi, who died shortly after the reconciliation.