The National Park Service supports a proposed 2,100-acre expansion of the Ocmulgee National Monument.
Now it's up to Congress whether to quadruple the size of the historic site.
Depending on the interest of Georgia's congressional delegation, that could take "several months or several years," according to park Superintendent Jim David.
According to a news release from the Park Service, the agency's Southeast Regional Director approved the findings of a study that recommends expanding the national monument in Macon.
That came after more than 3,200 people, groups and agencies commented on the proposed expansion earlier this year. All but one person were in favor of the expansion, according to the news release.
The Park Service recently completed a two-year study of land between their main park and a smaller site, to decide whether additional land should be added.
Native Americans from the Mississippi River arrived at the monument site in the year 900. They built ceremonial mounds and earth lodges, the park's biggest attractions.
David has said the expansion would preserve some of their sacred sites and make the park's Lamar unit, in southeast Bibb County, more accessible. It would also give visitors access to the park from the Ocmulgee River.
The expansion won't happen unless Congress votes to expand the boundaries and appropriates any money that's needed.
He said the office of U.S. Sen. Johnny Isakson has indicated support for the expansion and U.S. Rep. Sanford Bishop also sent a letter backing the expansion.
David could not estimate the cost of the expansion, but said much of the land would be donated.