A Cloverdale tribe granted federal clearance to build a casino on its homeland is moving forward with a gaming project but may downsize the scale of its plans to account for Sonoma County’s two existing tribal casinos, including the large gaming resort still taking shape outside Rohnert Park, a top official with the Cloverdale Rancheria said this week.

A casino on the rancheria’s newly designated sovereign land on the southeastern end of Cloverdale would likely be more modest than the Graton Resort and Casino next to Rohnert Park, Cloverdale Rancheria Tribal Administrator Vicky Macias said.

Contractors last month reached the halfway point on development of a 200-room hotel adjacent to the 340,000-square-foot, 3,000-slot machine Graton casino, one of the five biggest in the state. The Cloverdale’s tribe’s original 2008 plans envisioned a project of similar scale.

“For us to come in and build something that big, we don’t know if economically it’s in the best interests of the tribe financially,” Macias said in an interview. “I think at this time, it’s off the table.”

She said the last thing the tribe wants to do is “overbuild and never fill” its casino.

The size of the casino, she added, will depend on market studies. “Until we do our homework, we don’t know the full description of what the project will be,” Macias said.

The Bureau of Indian Affairs last week granted the Cloverdale Rancheria of Pomo Indians permission to create a sovereign homeland on 62 acres outside Cloverdale, the county’s northernmost city. Approval of the request, eight years in the making, represented the largest initial hurdle to the tribe’s plans for a casino-hotel complex.

The original plans called for a 575,600-square-foot complex consisting of a casino with 2,000 slots, 244-room hotel, 984-seat convention center, 1,300-seat entertainment hall and 3,500 parking spaces.

The tribe still must obtain a gaming compact for a casino from Gov. Jerry Brown, but has not yet begun negotiations, according to Macias. The compact also must be ratified by the Legislature.

Another potential hurdle could come if Sonoma County supervisors decide to challenge the action by the BIA to place the land into federal trust on behalf of the tribe, which makes the property no longer subject to state and local authority.

The supervisors will meet Tuesday, in a second consecutive closed session on the topic, to consider whether to try to stop the casino by filing a lawsuit challenging the federal decision.

Supervisor James Gore, who represents the area and who opposes a casino in Cloverdale, said the county is still weighing its chances of prevailing. He acknowledged it could be a long shot.

“Case law doesn’t bode well for being able to stop this from going forward,” Gore said Friday.

County Counsel Bruce Goldstein said even if the county files a lawsuit, there are new rules where “the land goes into trust and can be developed while the litigation is pending.”

Both county and city officials this week expressed a willingness to negotiate an agreement with the tribe to offset the casino impacts. Such deals could include tribal payments for providing police and fire services and potentially extending city water and sewer utilities to the casino development.