Sonoma County supervisors Tuesday unanimously approved a multimillion-dollar revenue-sharing agreement with the tribe that is building a casino next to Rohnert Park. ‘What we have before us is certainly a really good outcome of negotiations for the county,’ said Supervisor David Rabbitt, whose 2nd District includes the 254-acre Wilfred Avenue casino site.

Casino officials intend to expand in a few more years with a permanent gaming hall, a 150- to 200-room hotel and additional restaurants. The expansion is driven by a competitive threat to the south that will end River Rock’s monopoly on Indian gaming in Sonoma County. The Federated Indians of Graton Rancheria have started their long-stalled casino-resort in Rohnert Park just west of Highway 101, expected to open by late next year.

An $850 million financing package, said to be the largest in the history of Native American gaming, is now secured, the Las Vegas-based backer of the casino next to Rohnert Park announced Wednesday. The package will pay for the Federated Indians of Graton Rancheria’s 3,000-slot-machine casino and resort on Wilfred Avenue, according to Station Casinos, which will manage the facility.

Construction of an Indian casino next to Rohnert Park could start within months and it could be open to gamblers next year, the Las Vegas company that is financing the project said Tuesday. ‘We anticipate starting construction on the project this summer and opening by the end of 2013,’ Station Casinos said in its latest quarterly statement.

The new gaming compact giving the Federated Indians of Graton Rancheria the right to open a Las Vegas-style casino resort outside Rohnert Park pushes the relationship between the state’s tribes and its local governments into untested territory. That has roiled the Indian gaming community across California, where some fear it gives local governments too much sway over casino projects.

The Indian casino-resort proposed for the outskirts of Rohnert Park cleared a crucial hurdle Friday, securing the state compact it needed before construction can start. Gov. Jerry Brown’s signature on a gaming contract was one of the final governmental agreements that the Federated Indians of Graton Rancheria needed before moving ahead with the controversial $433 million project. It could have up to 3,000 slot machines, 5,500 parking spaces, a 200-room hotel and restaurants and bars. If built to completion, it would become Sonoma County’s largest private employer and one of its most costly developments.

Sonoma County Supervisor Shirlee Zane is fuming today over a vote by Rep. Lynn Woolsey supporting legislation Zane says will “open the flood gates to us becoming a Northern California Las Vegas.”