ST. LOUIS -- The National Park Service has chosen a vision for reshaping the Gateway Arch grounds that could include closing part of Memorial Drive to traffic, expanding the underground museum and taking in extra land on both sides of the Mississippi River.

In its release today of a 298-page "general management plan," the Park Service announces its direction for future development of the Jefferson National Expansion Memorial, the 91-acre riverfront park that includes the Arch and the Old Courthouse. The document is the result of more than a year of study and public hearings.

The next big step would be for the Park Service to sponsor an international design competition similar to one in 1947 that led to Eero Saarinen’s winning design of the Arch, the region’s reigning symbol. A jury of independent specialists would recommend a choice, and the Park Service would select one. Then Congress and local sources would have to find money.

The document still needs signatures of Park Service officials after a 30-day wait, but that action is considered routine.

The plan estimates it would cost about $305 million to complete what is in the plan, but warns that detailed design could boost the sticker significantly. That for an Arch and Expansion Memorial that cost about $35 million. The final piece of the Arch was hoisted into place in a ceremony on Oct. 28, 1965, although the grand staircase wasn’t completed until 2003.

Central to the new plan is solving an old frustration among locals and tourists — the hassle of walking from downtown to the Arch grounds. For decades, people have talked about building pedestrian bridges, closing streets or putting a lid over the Interstate 70 "depressed lanes." None have materialized.

The plan suggests closing as many as three blocks of Memorial Drive at Market Street, a busy intersection for daily commuters, tourists and baseball fans. Sandra Washington, a Park Service regional official and project manager for the plan, said preliminary traffic studies suggest it wouldn’t cause gridlock.

"We consider it an interesting option worth looking at," Washington said.

DANFORTH SPURS TALKS FOR ARCH REDEVELOPMENT

The study was spurred by former Sen. John Danforth, who in August 2007 urged regional and national leaders to "think big" in transforming the grounds with easier access and more activities, possibly include cafes, bike rentals, an aquarium or an amphitheater.

The Park Service was cool to the idea at first, but later announced its intention to eventually seek a design competition. It held public hearings earlier this year.

Danforth once offered $50 million from the Danforth Foundation to help underwrite a sufficiently ambitious plan. But in April, he said the Park Service planning fell "far short" and withdrew from the effort. On Thursday, a spokesman reiterated that statement, adding, "We wish all those concerned the best." He said Danforth had not seen the new document.

Expansion Memorial superintendent Tom Bradley said Thursday the review "gave us all a chance to step back and go through a methodical process. Everybody wants something that can actually happen, not have a big plan on a shelf... We want to make the park more relevant to today’s society, yet true to the reasons for which it has been protected."

THE ARCH CONNECTION TO DOWNTOWN

The idea for the Arch and surrounding grounds date to the 1930s, when Luther Ely Smith Sr. and other civic leaders pushed for replacing 40 blocks of the decaying 19th-century warehouses — site of the original village of St. Louis — with a sweeping memorial to President Thomas Jefferson. His promotion of the Louisiana Purchase from France in 1803 almost doubled the size of the United States.

In July, U.S. Interior Secretary Ken Salazar visited the Arch and said finding a way to better connect the monument with downtown is a "priority of President Obama," his boss.

The document released today would throw open almost all of the 91 acres for consideration, rather than roughly half as the Park Service had suggested in January. There still would be plenty of restrictions, including a ban on doing anything above ground on the sweeping lawn beneath the Arch. And there will be no sale of any federal park land, as Danforth originally had suggested.

But design competitors could offer ideas for visitor centers or museum buildings on the north or south ends of the Arch grounds. And it contemplates expanding the underground museum and building a museum entrance somewhere near Memorial Drive. Washington, the project manager, said there is room beneath the wide Arch lawn to almost double the size of the museum.

The plan also asks for ideas to include some of the riverfront in East St. Louis and the warehouse district just south of the Poplar Street Bridge in St. Louis. It also endorses a "water taxi" to ferry visitors back and forth across the river.

As for busy Memorial Drive itself, the plan says design competitors should consider closing at least the block between Market and Chestnut streets, in the direct view between the Old Courthouse and the Arch, or as many as the three blocks from Pine to Walnut streets.

Washington said any plan would have to keep street access to the Old Cathedral, owned by the Archdiocese of St. Louis. Closing part of Memorial, she said, and a building a lid over the depressed lanes would provide easy walking from downtown to the Arch grounds.