The lake-front campsite was a washout. The pottery mart was a bust. But now, thanks to the federal courts, the Umatilla Indian tribe has found another native American tradition to attract the tourist dollar.

The courts call it "on-reservation gaming." The Umatillas and their free-spending visitors use the more common name: "Bingo!"

Bingo may not precisely qualify as an ancient Indian tradition, but it is rapidly winning a central place in modern tribal lore for the Umatillas and scores of other tribes from coast to coast.

Thanks to recent court rulings that essentially exempt Indian reservations from state gambling laws, tribal councils nationwide are betting on bingo to put them in the chips.

Delegates to the National Congress of American Indians' annual convention here several weeks ago jammed a meeting room to hear members of the Indians' National Bingo Task Force report on how to set up a game.

Joe De La Cruz, a Quinault Indian from Washington who is president of the National Congress, said that one-fourth to one-third of the nation's 300 or so tribes offer bingo -- with several tribes operating games seven nights per week -- and that many more are likely to start soon.

De La Cruz said bingo is an economic godsend for tribes that have limited resources, minimal capital and high unemployment -- a description that fits many reservations today.

"It doesn't cost much to set up a bingo operation, and it creates a lot of jobs -- and boy, we need them," De La Cruz said.

Some tribes have taken up the bingo boom in grand fashion. Players travel north from Seattle by the bus load to the Tulalip tribe's bingo bar just off Rte. 5, where grand prizes can include a $30,000 recreational vehicle.

The Las Vegas of Indian bingo, though, is in upstate New York, where the Mohawks are building a $1.5 million emporium to seat 1,500 players. The Mohawks plan to offer a grand prize of $100,000, 100 times the maximum award permitted under the state law that governs non-Indian bingo operators such as churches and fraternal groups.

The Umatilla Bingo Salon near Pendleton, Ore. is more austere -- its top prize so far is $1,000 -- but tribal leaders have high hopes for a bingo bonanza.

"The thing about this is, it's something you can start with a few rented tables and chairs, and it brings in cash," explained Ron Halfmoon, the burly Umatilla treasurer.

Lacking money of its own and facing prohibitive interest rates, Halfmoon's tribe first tried to generate economic activity by developing a campsite at the reservation. They also hoped to score by selling crafts at a highway mart. Both projects had disappointing results.

Halfmoon said his tribe, like many others around the country, began thinking bingo after a 1982 Supreme Court decision upheld a ruling that Florida's bingo laws did not apply to games run by the state's Seminole Indians.

On-reservation gaming is immune from state regulation, the courts say, because of the Indian tribes' unique status as sovereign nations within the nation. The decision seemed to say that the federal government could regulate Indian bingo, but it has not done so.

The recognition of unique status for tribal games has created a backlash, particularly among competing church bingo games.

"This business is megabucks," said Suzan Shown Harjo, executive director of the National Congress. "And, like anything, there's competition and it becomes bucks versus bucks, and the legislators get into it."

Some state legislatures are considering bills -- which Indians say are legally invalid -- to restrict Indian bingo games to Indian players.

When such a law was proposed in Arizona, the Yaqui tribe, which has a lucrative bingo business in Tucson, announced that it would make every player an "honorary Yaqui" each night if the law passed. The measure died in the state senate.

The tribal bingo games have also been mildly criticized by the Indian community.

"I don't begrudge any tribe that finds a good way to make jobs," said Hank Adams, a leading Indian activist from Washington's Nisqually tribe.

"But still, you know -- it's not what I consider grounds for pride. I'd hate to think that 30,000 years of a proud culture have found their pinnacle in a bingo hall."