Wallace Stegner, the late historian known as the dean of writers on the American West, once said that our national parks are “the best idea we ever had. Absolutely American, absolutely democratic. They reflect us at our best rather than our worst.”

It’s a sentiment that resonates deeply in this community. For the same reasons national parks stand as America’s best idea, the Jefferson National Expansion Memorial and Gateway Arch that grace St. Louis’ riverfront arguably represent this city’s single greatest civic accomplishment. Their imposing and stirring presence touch all people. They remind us of the heights we are capable of reaching when we are at our best.

Today, the National Park Service — after 18 months of working with leaders and ordinary citizens, here and throughout the nation — has presented the clearest and most comprehensive blueprint since completion of the Gateway Arch for how that legacy can be renewed, reinforced, broadened and animated for future generations.

It comes in the form of the final “General Management Plan for the Jefferson National Expansion Memorial” —  a 298-page document that sets forth in detail how the Arch, the Old Courthouse and surrounding properties could be improved and administered over the next 15 to 20 years.

Here are some highlights:

• St. Louis’ riverfront once again will be the focus of an international design competition, akin to the 1947 contest that yielded Eero Saarinen’s plan for a park centered around his 630-foot stainless steel catenary arch.

• Designers will be asked to consider virtually the entire park grounds, roughly bordered by and including the Poplar Street and Eads bridges, the Illinois riverfront and Memorial Drive. The world’s most brilliant designers will be challenged to think not only of the park, but also the urban fabric of which it is a part.

• The competition reserves a significant place for integrating the Illinois riverfront into the park experience — an unrealized part of Mr. Saarinen’s vision for the memorial. Contestants also will consider the best way to upgrade the Museum of Westward Expansion Museum, now set beneath the Arch. The underground space could be doubled and get a dramatic new entrance west of the Arch.

• Multicolored maps identify geographic “zones” that set limits and invite solutions. The Arch and its principal grounds are referred to as the “original landscape.” Changes there are restricted to matters affecting visitor access and security. “Heritage and Visitor Amenities” zones — primarily on the north and south ends of the park and on the Illinois riverfront — are open to a broad range of design and program solutions. They could include a new architecturally significant visitor attraction as was proposed by former U.S. Sen. John Danforth.

•  Design solutions also are sought for “streetscapes and riverscapes” to overcome barriers that separate the park from downtown, the riverfront, Laclede’s Landing to the north and Chouteau’s Landing to the south. Much local attention has been focused on the future of Memorial Drive and the depressed lanes of Interstate 70. Designers have been given a clean slate on such matters; entrants may propose lids, pedestrian bridges, street closures, boulevard narrowing or whatever is deemed most effective.

Andrew Cutraro/Post-Dispatch

What’s next? Park Service regulations call for a “cooling off” period for the next 30 days to correct mistakes. Then, in late November, the Park Service’s regional director will come to town for a signing ceremony to mark the formal start of the process.

The Park Service and various partners and interested parties will begin organizing and framing the details of the design competition — a process that includes fundraising. The competition could be opened within six months and concluded within a year.

A jury of design experts will select the winning entry, although the National Park Service reserves the right of final approval.

Any makeover will cost serious money; the Park Service estimates more than $300 million in capital costs.

This complicated project will take time to complete, and it should. It must be handled carefully and done right. So far, there are reasons to think it will.

Regional leaders, the business community and advocates for the Park Service already have coalesced around the project in productive ways. Jon Jarvis, the new Park Service Director, has a record of keen interest in urban national parks. His boss, Interior Secretary Ken Salazar, said in a visit here in the summer that the project is a priority for President Barack Obama.

The secretary said he would “move heaven and earth” to have it completed in 2015, in time to celebrate the 50th anniversary of completion of the Gateway Arch.

That the plans and ideas released today are comprehensive and well-organized is in large part because of the persistent leadership of Mr. Danforth. In 2007, he exhorted the region and the Park Service to “think big” to re-energize this singular public space and civic asset.

The Park Service responded to the call — upholding its responsibilities as conservator of park lands and being a careful listener and imaginative partner with the public.

Designers and planners, to your drafting boards. Onward to the competition!

J.B. Forbes | Post-Dispatch