If you are a Tlingit Indian and you make your living hunting muskrat, and your village in Alaska spends $1,500 to send you to Washington to hear the president thanked for making your island a national monument - then there is something that justifies letting your friend whip out his Instamatic to take your picture in front of the White House.

In various parts of the city yesterday varied clumps of people gathered to celebrate being ethnic in America. They were all in town for unrelated events that brought native Americans from Alaska, Japanese Americans from San Francisco and Hispanics from Denver.

Mathew Fred, Tlingit Indian from the Raven Tribe, chief of all tribes on Admiralty Island (southwest of Juneau, Alaska) stood outside the East Room of the White House where he and two other tribal chiefs had presented President Carter with a blue felt lovebird vest and had anointed him Na'hoo-woo, "chief of the people in migration."

Elizabeth Fred, his wife, who wore native dress and bald-eagle pierced earrings (there are more bald eagles on Admiralty Island than in the rest of the country put together, someone explained) and Chief William Nelson (chief of the Dog-Salmon Tribe) and his wife, Martha, were nearby.

"Martha and I helped remove President Carter's jacket so he could put on the vest," said Elizabeth Fred with a clearly delighted smile.

"We're just lobbying to protect the way we live," said jean-clad Albert Kernak, an Eskimo from Napakiak in Alaska. He is a trapper whose father was a trapper and whose grandfather was a trapper and so on. He came to watch the presentation and to lobby for legislation to set aside for preservation a piece of Alaska about the size of California.

Congressman Morris Udall (D-Ariz.), a cosponsor of land legislation, was there along with people from "Americans for Alaska" or "The Alaska Coalition." And so was Jacques Costeau who flew in from Paris.

"We're here to tell people we want to preserve the land," said Chief Fred. "We're told if we're kind to the land and the sea, the land and the sea will be kind to us - pure logic."

He is a retired pediatrician, a thin dark man, soft-spoken with rimless glasses and a gentle manner. He was constantly greeted last night by friends in the Caucus Room of the Russell Senate Office Building. He is Clifford Uyeda, the national president of the Japanese American Citizens League (which everyone referred to as "the JACL" as easily as they would to "the Jaycees."

Everyone at the reception for Japanese Prime Minister Masayoshi Ohira, currently visiting Washington, seemed to know everyone else, talking of friends and tennis and the like.

"Americans cannot understand the difference between Japanese Americans and Japanese nationals," Dr. Uyeda, who lives in San Francisco, said as he stood in the long but quickly moving reception line past the prime minister. "We look at Japan as a land of ancestors, but we are American. Our interests are American, but every American has an ethnic heritage and you really don't have to lose it to be a good American."

He passed Sens. Daniel Inouye and Spark Matsunaga of Hawaii, both Democrats, both of who pumped his hand. "This guy is doing a great job," said Rep. Norman Yoshio Mineta (D-Calif.) as Uyeda moved through the line.Ohira shook his hand and smiled and Uyeda moved past, not even stopping to volunteer his title to the prime minister.

As Ohira spoke before the crowd in slow, thick English, Mari Taki, from Chicago, remembered sitting around the dining room table with her family in Vallejo, Calif., during World War II and discussing their forced move to a relocation camp.

"My father was sharpening his knife and the tears were falling on his whetstone and he said, 'I've raised you all to be good Americans and now your country is betraying you,'" Taki said, calmly, Bloody Mary in one hand, a camera swinging from an armstrap on another. "I just wish he could be here to see we've all made good livings and we've met the president."

"I'll go anywhere to be with LULAC," said Al Valenzuela, who works for an organization affilliated with the League of United Latin American Citizens, Valenzuela came from Denver to the 50th anniversary banquet of the oldest Hispanic organization, held at the Washington Hilton last night.

But not enough people know about the organization and what it has done for the civil rights of Hispanics, said president Eduardo Penas. (One guest compared it to the NAACP.)

So Penas held a press conference yesterday afternoon to tell more. But he was not unhappy. Several senators sent representatives to the dinner. House Minority Leader John Rhodes (R-Ariz.) made it to the reception. The keynote speaker was former New Mexico Gov. Jerry Apodaca. And the organization has 40,000 members nationwide, including farmers, professionals and business people, he said. Penas has met three times with Mexican President Lopez Portillo in less than a year.

The dinner was begun with a speech in Spanish by the master of ceremonies, Roberto Ornelas, who said that unfortunately there were people in the audience who did not speak Spanish. He then abruptly switched to English and said, "For the benefit of you monolinguals, welcome to the 50th anniversary celebration." There was much smug laughter and applause. CAPTION: Picture, President Carter in a Tlingit tribal vest