The Prince George’s County Planning Board voted late Thursday to approve key elements of a project that would include the county’s first Whole Foods Market.

The unanimous vote, one of the final steps in a long and contentious approval process, means that the developer, Calvin Cafritz Enterprises, might be able to move forward soon with permitting and development of the 37-acre site in Riverdale Park.

The project, however, still faces potential hurdles. Some residents object strongly to the development and are likely to appeal the decision, which could delay plans to break ground in August.

“I expect that there can be all kinds of appeals. Those who oppose this will continue to oppose it, but I am confident that it is going to move forward,” Riverdale Park Mayor Vernon Archer said.

The Planning Board voted just before midnight Thursday, after a seven-hour hearing that was dominated by the concerns of people living close to the site. The five-member panel reviewed conditions proposed by Riverdale Park, University Park and College Park, concerning landscaping, bike lanes and the location of a bridge entrance to the development.

“This was the largest single hurdle to getting this done. We have got lots of things to get done, but you feel like you are on top of the mountain now,” Archer said. “I am happy, excited, ecstatic, relieved and exhausted.”

The $250 million project would include the Whole Foods store, multifamily housing, a hotel, and office and commercial space on what is now wooded land along Route 1 and north of East-West Highway.

Two weeks ago, the board approved a preliminary site plan, and last week, it started to review a more detailed plan. The panel continued and concluded that review with the hearing Thursday. The board has to adopt a resolution to make its decision official.

If opponents appeal, the challenge would be heard by members of the County Council, who convene as the District Council to deal with land-use matters.

Some residents say they object to the proposed density of the project and worry about the additional traffic it would bring to the congested Route 1 corridor.

“The development is inevitable. It is a question of what suits that site,” said Susan Dorn of University Park, one of the residents who are considering an appeal.

The vote Thursday was a win for County Executive Rushern L. Baker III (D), who is backing the plan and sees the project and the coming of Whole Foods as evidence that Prince George’s can attract upscale retailers.