American Canyon’s long-anticipated town center is back on the shelf and won’t return to the public eye for at least a few more months.

McGrath Properties of Oakland, which withdrew in June its application to develop 100 acres around the old Standard Portland Cement Corp. ruins, says it wants to return with a proposal that would expand the development to the north, up to Watson Lane. McGrath representatives said they won’t file the new application before the land — about 250 undeveloped acres in unincorporated Napa County — is within the city borders.

So far, however, only 30 acres of the future Town Center, a property that belongs to the Jaeger family of Napa, are within American Canyon’s borders.

“We’re looking forward to the annexation of the lower Watson and the other parcel,” said Deborah Castles, McGrath Properties vice president of development and asset management.

The Napa Local Agency Formation Commission, the agency that approves boundary changes in the county, will have to approve the annexation of the rest of the property. Napa LAFCO must first sign off on American Canyon’s new sphere of influence, the area that includes county lands slated for annexation in the coming years. While the city has yet to file an application to amend its future boundaries, city and county officials signed an agreement last year that American Canyon’s boundaries would include the larger Town Center development.

American Canyon City Manager Rich Ramirez last week said the objective is to have the land annexed by early 2010.

“We’re pretty much on track,” he said.

City and county officials negotiated an agreement last year on the city’s future boundaries, an agreement the American City Council ratified last August. What’s left are “fine points,” according to Napa County Board of Supervisors Chairman Mark Luce.

In a letter to city officials dated June 4, Nancy Watt, Napa county’s executive officer, said Napa County would like to retain more than 50 percent of all future property tax revenues generated by the land in question. County officials also want to transfer a share of the county’s state-mandated affordable housing obligations to the city.

Last Tuesday, American Canyon City Council members voiced their support for the project, though they want a larger share of property tax revenues.

The development of the city’s town square was first discussed in the late 1990s. About1,500 American Canyon residents in 1999 voted for a town center at the former basalt plant ruins.

Structures remaining at the former industrial site include silos and a rotunda building, familiar sights to drivers on Highway 29. The structures have drawn the attention of Napa County Landmarks and American Canyon resident Lisa Lindsey, who recently launched a grassroots signature campaign to save them.