It was not really much of a fight. It was late at night and there was a lot of liquor around and "altercation" is the word Mark Oliphant prefers. An altercation that ended when Oliphant, a non-Indian but nonetheless a life-time resident of the Port Madison Reservation, was pulled away by a newly appointed officer of the Suquamish tribal police.

Nabbed by a tribal policeman, Oliphant still bristles at the memory. "Right on the little league ball field," he said recently, thumping his table at the local bar, "where I hit my first home run."

Oliphant was not cooperative. Oliphant was charged with resisting arrest and assault on a police officer and was locked up in jail for the next five days. And last month, wearing his best brown corduroy suit, Oliphant went to Washington to watch the Supreme Court hear the case that may have turned his late night altercation into a major test of the balance of power on America's Indian reservations.

The issue starts off simple: Do the six Suquamish tribal police, whose headquarters is a cramped office on the main street of this tiny Puget Sound community, have the authority to arrest non-Indians on the reservation.

And once arrests are made, does the Suquamish trial court, which is usually convened by turning an office table sideways and clearing away the coffee pot, have the authority to try non-Indians - who have no direct voice in the making of Suquamish law - and sentence them to jail?

Those two questions, presented to the nation's highest court in an era of unprecedented controversy over Indian claims to land and its resources, contain a staggering array of legal implications - "so far reaching," said a Tacoma city official, "that you don't even want to contemplate it."

If the Suquamish are granted criminal jurisdiction over non-Indians, the decision might well apply to the 133 other tribal courts now functioning in reservations across the country.

Add that, in turn, could likely lead to a grant of civil jurisdiction, handing Indian tribes the real reins of power on any reservation - control over zoning, local taxes, development permits, and the other vitally important government functions now being tested by Indians (and fought by non-Indians) on reservations all over the country.

The small Suquamish tribe, whose numbers on and off the reservation are estimated at about 500 by tribal leaders (and at half that by their opponents) would have full police power and local governmental authority over the Port Madison reservation's 3,000 present non-Indian residents and the thousands more projected to move in as the huge Trident missile submarine base reaches completion nearby.

The even smaller Puyallup tribe, although the boundaries of its reservation are in dispute, arguably could claim authority over the whole port of Tacoma and about 28,000 of the city's non-Indian residents.

The Northern Cheyenne Indians, whose land in Montana holds a untapped fortune in underground coal, could keep their reservation out of the hands of the thousands of non-Indians that coal production might attract.

The possibilities are enormous. "Every Indian in the United States is sitting on the edge of his chair," said Chet Irgens, a Montana Blackfeet Indian who served as chief of the Suquamish police department. And the Suquamish tribal chairman, Navy metals inspector Richard Belmont, said softly at the end of a long conversation: "This is it, man. This is the biggest shot. This is the whole ball-game."

The national controversy over Indian claims has raged with a special fury in this state ever since U.S. District Court Judge George H. Boldt ruled four years ago that 123-year-old treaties entitled its Indian fishermen - quarter of all the commercial fishermen in the state - to half the annual salmon catch. Amid the ensuing public outcry, non Indian protests, and occasional gunfire over, Puget Sound, two Washington congressmen have sponsored bills (one of which would simply abrogate all treaties) that opponents rank high in the so-called "anti-Indian backlash" legislation.

Backlash is shorthand. In the midst of a society based on economic clout, individual civil liberties, and majority rule, the Indians are wielding contracts - treaties - that promised cultural and geographic separation, and enforce them. The bills and the court battles are a head-on collision in the making a 1970s clash between two American promises, and that is how they talk about the Oliphant case in this rain-polished waterside town.

"The Constitution of the United States," Oliphant declared, his voice firm enough to be heard at the next table, "doesn't apply in this town right now. It's a punch in the nose, is what it is."

Plumber Oliphant is 25, husky and mustached. The son of a house painter, he grew up on "fee patent" land - a privately owned reservation plot bought by his non-Indian parents under a 19th century federal law that allowed Indians to receive individual allotments of tribal land and then sell the land to whites. Under this arrangement, non-Indians have bought more than half the Port Madison reservation, making it, like many others in the country, a checkerboard of tribal, individual Indian, and non-Indian ownership.

In tribal matters and tribal law, Oliphant does not have a vote. Because he is not at least one-eighth Suquamish, the tribal minimum for membership, Oliphant was not permitted to vote either for the current Suquamish leadership or for the law code under which he was arrested. He is also not eligible for duty on tribal juries.

The same rules apply to Olphant's friend Daniel Belgarde, who was arrested in October 1974 after he allegedly led tribal police on a wild two-hour chase that ended when his pickup truck collided with a police car, Belgarde was charged with destruction of public property and "recklessly endangering another person"; the Suquamish code does not yet include a set of traffic laws. He has become a co-petitionner in the case, declaring, like Oliphant, that he cannot be arrested by a government that will not let him vote.

To this Belmont, and the tribe he heads, respond simply.

"We never have forced people to come and live on the reservation," Belmont said. "We had a treaty that established our boundaries. Either we're a responsible tribal government, protecting our reservation, or we're not a government . . . and if we're not a government, how the hell did the United States sign a treaty with us?"

The much-disputed law code, Belmont pointed out, is a relatively unexciting document that by government order may not contain any violation of federal law. And Bureau of Indian Affairs officials say that, overall the quality of tribal justice is not worse than in local white courts all over the country.

Now clipped between the covers of a black loose-leaf binder, the code begins with a preamble ("we, the people of the Port Madison reservation, hereby establish this Code of Laws . . . to protect the rights of all persons within the boundaries of the Port Madison reservation . . .") and goes on to outline areas of the law that range from breaking and entering to cruelty to animals.

"If anybody is afraid of our tribal court, just don't break any law," chairman Belmont said. "You'll never see it."

An irony in all this crystalizing the conflict of values and inflaming tempers on both sides, is that although Belmont's family owns land on the Port Madison reservation he does not live there. He lives in Bremerton, 30 miles away. There is little work on the reservation, Belmont said, which is why more than half the Suquamish tribe lives outside its boundaries.

Suquamish leaders speak of the law allowing reservation land sales to non-Indians as one more government blow - "an act of termination in disguise," Belmont called it - that ultimately betrayed buyer and seller alike.

Indians, who often could not receive loans on their property because no bank could foreclose with the federal government as trustee sold much of the land under the pressure of mounting poverty. Whites bought in at the federal government's invitation, having no idea that in 1978 a U.S. solicitor general's friend-of-the-court brief in the Oliphant case would describe their status as "in one sense . . . no different from the situation of anyone residing in a foreign country; absent special extra-territorial arrangements, he must submit himself to the law in the courts of the country which he has chosen to enter.

The land of the Port Madison reservation, the Suquamish insist, is theirs, has been theirs since Jan. 22, 1855, when the treaty of Point Elliott was signed at the place the Indians called Muckl-te-oh. And the Suquamish say that within the boundaries laid out by that treaty, whitr settlers' rights and majority rule - the cries that have accompanied the confiscations of Indian land for 200 years - are irrelevant.

"What it does is to disenfranchise American citizens," said Washington state Attorney General Slade Gorton.

"If you went by majority rule the Indians would have been finished a long time ago," said Barry Ernstofs, the tribe's attorny.

"It's Hitler," said Philip Malone, attorney for Oliphant and Belgarde.

"They knew it was the reservation when they moved here," a young Suquamish man said.

And in the bar overlooking the quiet waters of Puget Sound, a 61-year-old man, hald Suqamish himself, clapped Olipant on the back and said he was an American citizen and he'd be damned if he'd see the tribe become a second government. "These goddamn Indians think they can run this . . .," the man said slowly, bringing his face close to Oliphant's. "They're crazy."