SACRAMENTO — The plan to build one of California's largest casinos just outside Rohnert Park moved to the verge of fruition Thursday when the state Assembly approved a gambling agreement to allow work to start on the project.

The Assembly ratified the agreement between the governor and the Federated Indians of Graton Rancheria, called a compact, on a 64-3 vote with no discussion. That sends it on the federal government for final approval, which most experts believe is virtually assured.

Greg Sarris, the tribe's chairman of 20 years, did not respond to a request for comment. But tribe supporters indicated the Legislature's ratification of the compact had been seen as the key remaining step for one of the county's most controversial projects in decades.

"Greg Sarris finally delivered what he always promised people," said Susan Moore, of Santa Rosa, who leads an informal community advisory group to the tribe. "That is, a business that will benefit Indian and non-Indian communities alike."

Labor leaders, who have been the biggest boosters of a project that could cost more than $700 million, were delighted, hailing the predictions of 900 construction jobs and more than 2,000 permanent union positions the tribe says will be created.

"I'm very happy that we're near the end of what has been a long and very difficult process," said Jack Buckhorn, secretary and treasurer of the Building Trades Council of Sonoma, Lake & Mendocino.

"It looks like the final major hurdle has been cleared," Buckhorn said. "The jobs and prosperity that this project will bring to Sonoma County will be substantial."

Casino opponents, who have fought the project for nine years, said their efforts would continue, though they were back on their heels.

"We're certainly not giving up," said Petaluma Councilman Mike Healy, who spoke against the compact at legislative hearings last week. Attacking the accuracy and completeness of environmental reports done for the project will be one avenue of opposition, Healy said.

Also possible, he said, is the revival of a lawsuit alleging that the federal government's 2010 decision to take into trust the tribe's 254 acres outside Rohnert Park improperly exempts the site from state laws.

The tribe on Thursday issued a statement calling the ratification an "important milestone" and highlighting the "much-needed services" that revenues from the 3,000 slot-machines would provide its members. It also called attention to what it described as an "unprecedented level of revenue sharing" with Rohnert Park, Sonoma County and tribes that do not run casinos.

The compact, in a first, requires that a range of financial agreements to address the casino's impacts be in place between the Federated Indians and Sonoma County and Rohnert Park before work work can begin. The tribe has a 20-year, $200 million agreement with Rohnert Park and an agreement to negotiate a similar type of deal with the county.

The compact also requires the tribe to contribute what eventually will reach $12 million a year into the Revenue Sharing Trust Fund for tribes without gambling operations. That fund, which the Federated Indians once drew from, too, now has a $28 million deficit.

In hearings last week, Jacob Applesmith, a senior advisor to Gov. Brown who negotiated key parts of the compact, called the amount of money the tribe will direct to local agencies and the state fund "unprecedented."

Voting no on Thursday were Democratic Assemblymembers Michael Allen, who is running for re-election in the newly-formed 10th District and as a labor leader supported the casino; Mariko Yamada, running for re-election in the newly-formed 4th District, which includes Rohnert Park; and Jared Huffman, who is aiming to succeed Lynn Woolsey in the newly-drawn 2nd Congressional District.

Assemblyman Wes Chesbro, D-Arcata, voted yes. His redrawn district will include Santa Rosa.

The compact, which Gov. Jerry Brown signed May 27, was approved 34-4 by the state Senate Monday. It moved speedily and without drama through the Legislature. Experienced Sacramento observers had predicted it could be a six month process for what Huffman once said would be one of the most controversial compacts ever. Instead, it took little more than a month.

The development leaves just one governmental hurdle for the tribe before it can start work on the project. That is the approval of the compact by the federal Department of the Interior, which has 45 days to ratify or reject it.

"I would put the odds at 99 percent" that the Interior Department will approve it, said Santa Rosa attorney Anthony Cohen, an authority on Indian law and tribal gaming.

"The attorneys for the tribe, the state, and the Secretary of the Interior all have the benefit of very recent court decisions clarifying the federal legal standards that gaming compacts have to comply with so it's unlikely that they will see things differently," Cohen said.

If the Department of the Interior does not reach a decision on the compact within 45 days, it automatically takes effect, Cohen said.

Station Casinos of Las Vegas company has bankrolled the tribe's venture so far with more than $200 million and will manage the casino for its first seven years. Company officials declined to comment Thursday.

The company, however, has said it wants to start work this summer. The approval of the project issued in 2010 by the National Indian Gaming Commission requires ground to be broken only between April 15 and October 15, or what is considered the dry season.

Work cannot start until the county and the tribe sign an agreement to address the casino's impacts, which they have 90 days to do should the Interior Department approve the compact.

Tribal representatives said last week that a six-story, 200-room hotel that is envisioned as part of the project will be built at an unspecified later date.