For 19 years, tax assessor Rubin White has cast a covetous eye across the Poteau River at a thin strip of land in what Arkansas says is Arkansas

No, it is Oklahoma, says White, who asserts that the land downstream that Arkansas gave to the U.S. government for a park was not Arkansas' to give. In his taxman's eye it was and should again be Oklahoma.

Now, after 19 years and three Oklahoma state attorneys general, Rubin White is finally going to get his day in court-the U.S. Supreme Court-to settle the bizarre boundary dispute between the two states.

While such disputes between states-they are numerous and endless-usually spring from rivers that change course or surveyors who made errors this one has its origins in Indian treaties, good old-fashioned frontier lawlessness and a woman named "Coeaine Annie."

In the 19 years that White has been tax assessor for LeFlore County, Okla., he has seen the old "Choctaw strip's" cardboard cutout homes and shipping crate shanties replaced by furniture factories, a forging plant, a tubing warehouse and a barge-docking facility.

"Gosh dog, I don't know what it's worth now," says White.

But available evidence indicates that the 57 acres in Arkansas or Oklahoma would nearly double the tax base of the seedy and suffering Arkoma high school district and add between $75,000 to $80,000 to the tax coffers in largely rural LeFlore County. Taxes are now paid to booming Sebastian County, Ark., where Fort Smith is located. In Arkansas, the whole issue is taken somewhat lightly. It is viewed as frivolous issue that comes up during election years in Oklahoma. On a more serious note, the legal action against Arkansas is seen as motivated by a desire for revenge after Arkansas' pasting of Oklahoma 31 to 6 in the 1978 Orange Bowl football game.

The story begins in 1820, in the Treaty of Doak's Stand. The Choctaw Indians and the U.S. government agreed in that treaty that if the Choctaws would leave Mississippi, they could have their own nation in what is now Oklahoma. The 1830 Treaty of Dancing Rabbit Creek firmly fixed the Choctaw's boundaries forever-for as long as the grass would grow, the wind would blow and the water would flow.

Choctaw land, it was said, would never become part of a territory or state.

The trouble was that the Arkansas and Poteau rivers effectively cut off the Choctaws from 57 acres of their land between the rivers and the western edge of Fort Smith.

The land soon became a refuge for riffraff, scoundrels, cocaine traders (Annie being the most notorious) and assorted other criminals who would raise hell, or worse in For Smith and then step back across the Choctaw boundaries that kept them safe from the authorities.

These trespasses occurred despite the best efforts of hanging judge Isaac Parker-87 swung from his gallows-who could see "Coke Hill" from his courthouse.

A congressional committee would eventually declare the 15 acres of Coke Hill "a menace to the health, peace and morals of Fort Msith," and Congress gave permission to police it.

In 1905, Congress went even further. Without consulting the Choctaws, it gave Arkansas permission to extend its boundary to the Poteau and Arkansas rivers. A week later, Arkansas did so.

Two years later, Oklahoma, which took in the Oklahoma and Indian territories, became a state after negotiating with the Indians. It was 57 acres smaller than it once could have been. Now Oklahoma wants those 57 acres back.

In papers filed in the Supreme Court, the state argues that while Congress permitted Arkansas to extend its boundary, it did so for police purposes only, and only until Oklahoma became a state. Oklahoma argues that Choctaw rights were explicitly preserved in the boundary legislation and that Indians' rights of sovereignity kept the land theirs-not Arkansas'. Thus, as Indian territory, it should have become a part of Oklahoma.

"Strained," is the official Arkansas reply to Oklahoma's argument. Arkansas adds that in the time that has passed, Oklahoma has lost any claim to the land. The state does, however, concede a contradiction: Deeds for the disputed land continue to be filed in LeFlore County, Okla., even though the land supposedly is in Arkansas.

For its part, Arkansas likes to cite the LeFlore County judge who, decades ago, enjoined one of Rubin White's predecessors from holding a tax auction of property in the disputed acreage for nonpayment of taxes to LeFlore.

Las month, the Supreme Court rejected Arkansas' request to dismiss Oklahoma's claim out-of-hand. The court ordered the state to file a full, formal response to Oklahoma next month.

It is not known what the court will do beyong that, but clearly some people hope it will uphold Indian treaty rights in a dispute that no longer has anything to do with Indians.

One problem for LeFlore County, should it get the land, would be police and fire protection because the 57 acres are still as cut off from Oklahoma as Cocaine Annie was from the Choctaws.

But people like Rubin White and Glen Lackey the superintendent of the hard-pressed Arkoma High School district, still want the land. Lackey says the added tax base-almost equal to the district's current one-could help him float bonds for much-needed school facilities.

Then there are the homeowners now living in Arkansas who would receive tax exemptions under Oklahoma's homesteading laws. Veterans could get tax breaks. And then there was the woman who tole a reporter once, "I always wanted to be an Okie, anyway."

"I'd just as soon stay in Arkansas," says a sailor at a U.S. naval training center in the disputed zone.

Such is the rivalry between Arkies and Okies? "Not really," says Oklahoma Attorney General Larry Derryberry, who filed the action. "If we couldn't have the land, we'd want Arkansas to have it." CAPTION: Map, no caption, By Dave Cook - The Washington Post; Picture, Rubin White, left, and Glenn Lackey study map with Arkansas in background. By Bill Curry-The Washington Post