Work began Monday at the site of the planned Indian casino on Rohnert Park's northwest outskirts.

The modest start, some tilling of the earth, was nevertheless a concrete sign that after nine years of controversy, legal battles and legislative, bureaucratic and regulatory hurdles, a casino resort may rise out of grassy fields in the Santa Rosa Plain.

The "grading of approximately 64 acres .<th>.<th>. signals the start of the nearly 900 construction jobs that will be created by the tribe's project," the Federated Indians of Graton Rancheria said in a statement.

Though the tribal chairman, Greg Sarris, did not respond to requests for further comment, the development is a landmark event for the tribe, which reached a nadir in 1958 when its rancheria was terminated by the federal government.

Resurrected from a handful of people, the tribe won restoration of its status in Congress in 2000, at which point it declared it had no interest in gambling. In 2003, saying other economic ventures had proved unfeasible, it announced its casino plans, which ultimately led it to the current site on Wilfred Avenue, a stone's throw south of Home Depot.

On Monday, questions remained about whether the work was starting ahead of required approvals.

The tribe's 254-acre Wilfred Avenue property is considered a reservation by the federal government and exempt from virtually all local and state regulations. But some official statements and documents conflict with other accounts of what must happen before work starts.

County officials said they believed the tribe had the ability to move ahead. But they expressed frustration that it had done so before it had entered talks with the county about ways in which the tribe would minimize the impacts of the project.

"We understand that there was not an legal impediment to begin construction," said Supervisor Shirlee Zane. "But it would have been more responsive to the community concerns to wait until we have a comprehensive agreement in place."

The commencement of preliminary work "points to the need to get comprehensive mitigations and monitoring in place as quickly as possible," Zane said.

The large tractor-tiller moving around the site Monday was preparing the site for grading, said David Sawyer, a representative of the tribe's environmental consulting firm, Sacramento-based Analytical Environmental Services. Sawyer and a biologist were at the site to monitor the work.

The tribe said it had chosen Sylmar-based Tutor Perini Building Corp. as its general contractor. The company, in which Sen. Dianne Feinstein's husband's investment firm is a major shareholder, has built several of Station Casinos' projects, including Thunder Valley Casino near Sacramento.

The agreement, or compact, between the state and the Graton Rancheria allowing the tribe to operate a Class III casino — with slot machines — is awaiting final approval by the federal Department of the Interior, which has not announced a decision.

The compact requires the county and tribe to reach an agreement on how the tribe will financially address the impacts of the planned 3,000-slot machine, 317,750-square-foot casino. A hotel is planned for a later date.

The compact says that "before the commencement of a project" the tribe "shall enter into enforceable agreements" with Rohnert Park, which it has done, and the county — which it hasn't done.

And at hearings in May in Sacramento, a senior advisor to Gov. Jerry Brown said that work on the project could not start until that county-tribe agreement is in place. County officials have said that negotiations are to begin once the federal government makes its decision.

Monday, they said they still foresee constructive talks leading to measures by the tribe to adequately address issues ranging from the effect on groundwater to the casino's impact on traffic and crime.

"I'm hopeful that we're going to be able to negotiate in good faith regardless of this action to make sure we've got these mitigations in place," said 5th District Supervisor Efren Carrillo.

The tribe on Monday said Sonoma County Counsel Bruce Goldstein had confirmed at a public meeting at the county Board of Supervisors last week that "the tribe has the right to start construction of the project prior to that agreement being concluded.

Goldstein did say that. He also said at that meeting that he did not see in the compact anything preventing the tribe from starting work before the agreement was reached.

However, he added that he didn't know whether the state had a separate requirement of which he wasn't aware. If it does, Goldstein said on Monday, "That's up to the state."

A spokesman for the governor, Evan Westrup, said in an email that "We are not aware of a compact breach." In response to a question seeking clarification of the statement by senior advisor Jacob Applesmith, he said "We have nothing else to add."

Casino foes said Monday's development showed the tribe had broken its word and was ignoring the deals it had agreed to.

"Obviously the compact doesn't mean anything because they weren't supposed to break ground until they were done negotiating with the county," said Chip Worthington, a Rohnert Park pastor who has led the opposition for nearly a decade.