Prince George's County leaders started dreaming two decades ago of turning an old gravel pit on the shores of the Potomac River into their own Georgetown waterfront.

The property near the Woodrow Wilson Bridge was going to be a world trade center at one point. One developer proposed luxury villa estates. Another called for a marina and a yacht club.

But for every idea offered over the years, there was only more failure and disappointment. Yesterday, that history seemed destined for burial.

National Harbor developer Milton V. Peterson announced a $560 million deal with Nashville-based Gaylord Entertainment Co. to build a hotel and conference center on the property. The 40-acre complex would feature 2,000 hotel rooms and a 400,000-foot conference center. Retail shops and restaurants would be located inside a climate-controlled atrium.

Gaylord, which owns the Grand Ole Opry and the Opryland Hotel and Convention Center, is the first tenant announced for the 534-acre National Harbor development. The company also is building hotel and conference centers in Orlando and Dallas.

"We have provided what we promised three years ago almost to the day," said Steven B. Peterson, project manager for National Harbor and Milton Peterson's son.

Steven Peterson said construction should begin this year. The center is expected to be completed and ready to open by 2004.

The Northern Virginia-based Peterson Cos. purchased the National Harbor property three years ago from the federal Resolution Trust Corp. after a previous developer defaulted on a loan and turned over the deed to avoid foreclosure.

The Peterson Cos. proposed a grand resort on the Potomac River with hotels, a conference center, offices, upscale shops and restaurants and a waterfront promenade. The plans have won the backing of key state and county officials, including Gov. Parris N. Glendening (D) and County Executive Wayne K. Curry (D).

"I think that there's been a great deal of skepticism," said Prince George's County Council member M.H. Jim Estepp (D-Croom). "A lot of people did not think that parcel would ever be developed. That's what made it ripe for critics on both sides of the river to oppose" National Harbor.

The project was approved by the County Council in 1998, and last year Congress removed the remaining hurdle the developer had faced by eliminating federal oversight of the project.

The developer will not have to seek additional approval for the conference center because the council created special rules to speed the review process for National Harbor.

The conference center is being constructed on the waterfront portion of the National Harbor property.

James H. Burch, a developer from Fairfax County, was the first to try to develop the property.

He proposed his "Bay of Americas" project in 1980 after buying the land from the widow of Lewis Egerton Smoot, whose sand and gravel company dominated construction in the Washington area for decades.

The Smoot company mined the land that is now National Harbor, and some of the old equipment rests at the bottom of Smoot Bay, a man-made cove created by the mining activity.

Burch proposed a planned commercial and residential development with town houses, offices, nightclubs and pavilions over the water.

He had planned to start construction in 1993 on the development, but it never happened.

James T. Lewis, who also developed in Fairfax County, then tried to build on the property. He envisioned a port town with small shops and restaurants on the waterfront.

Plans for his "PortAmerica" project called for a 52-story tower that would be home to Washington's World Trade Center.

But Lewis ran into trouble with the Federal Aviation Administration, which forced him to scale back the tower for fear it would interfere with air traffic. And he had financial difficulties that eventually forced him to abandon his plans after constructing a marketing center on the site.

"It was really sad. It was a very ambitious plan," said Sue Mills, a member of the County Council from 1978 to 1995. "But those were the times. A lot of people went under."

Peterson cleared the vacant center left from the failed Lewis project shortly after purchasing the land.

"Prince George's County's time has come," Estepp said. "I think the skeptics will see that this is unfolding as Peterson described, and it's not some type of bait and switch."