Cecilia M. Vega, Chronicle Staff Writer

Contra Costa Supervisors will reveal their hand Tuesday when they take their first formal vote against urban gaming in a county that could be home to bustling casinos.

Fearful that Contra Costa is on its way to becoming "casino central," supervisors are expected to vote unanimously to denounce gaming and the creation of any new casinos in their midst.

While the move is largely symbolic because local governments -- least of all the supervisors -- have no direct say in casino creation, county officials hope presenting a united front against gaming will persuade the federal government not to turn three Contra Costa sites into Indian reservations where gambling would flourish.

"Many people are focusing on the benefits and not taking into consideration the short- and long-term costs of turning West Contra Costa County into casino central of California," said Supervisor John Gioia, whose district includes the proposed casino sites in San Pablo, North Richmond and the former Navy fuel depot at Point Molate.

Contra Costa initially faced the prospect of having three Las Vegas-style casinos on its turf, but last month the Lytton Band of Pomo Indians scaled back their plans to expand Casino San Pablo to instead include an upgrade of the existing card room. The two other proposals are working their way through the complicated federal process of turning the properties into trust.

"It seems to me that this is the time to make our opinion known," said Supervisor Gayle Uilkema, who along with Gioia will present the matter to the board.

Supervisors also are poised to support state and federal legislation -- including a bill proposed by Sen. Dianne Feinstein -- that would curb urban gambling. Feinstein's measure would require the Lytton Band of Pomo Indians to follow state and federal approval procedures most commonly used under the 1988 federal Indian Gaming Regulatory Act.

Urban gaming was the topic of a county workshop last year and many supervisors have since spoken out individually against it, saying the potential for traffic congestion, increased crime and impacts on social services outweigh the creation of new jobs.

Now, however, supervisors are hoping that an official stance against casinos will persuade the Bureau of Indian Affairs and Interior Department, which approve the land trusts, to see things their way.

"An urban casino is incompatible in an urban county," Uilkema said.

Hundreds were expected to gather Thursday night for an environmental impact hearing in Richmond and to comment on the proposed casino at Point Molate, where an Emeryville developer backed by Harrah's and the Guidiville Band of Pomos want to build a resort with 3,000 slot machines.

The Scotts Valley Band of Pomos also are nearing completion on an environmental study to build an 1,800-slot machine casino in an industrial area in unincorporated North Richmond.

But backers of those proposals say they aren't worried that a vote by the county supervisors would affect their chances.

"Their simple view may not have too much of an impact," said Jim Levine of Upstream Development, the developer behind Point Molate.

Richmond City Councilman Tom Butt, whose city voted to sell Point Molate to Upstream for $50 million, said the county had nothing to lose by voting against urban gaming.

"I respect their opinions," he said, "but it's a lot easier for them to take that position because they don't have a lot to gain from these casinos. We do."

E-mail Cecilia M. Vega at cvega@sfchronicle.com.