1962 aerial photo of grounds where Gateway Arch would be constructed.

“Eero Saarinen: Shaping the Future,” a major retrospective on the brilliant career of the Finnish-American architect, closed Monday after a lengthy run at Washington University’s Mildred Lane Kemper Art Museum.

The program concludes just as the National Park Service puts the finishing touches on a plan for the future of the Jefferson National Expansion Memorial — home to Mr. Saarinen’s greatest work, the Gateway Arch.

It proves that we have only to look at the process that yielded Mr. Saarinen’s masterpiece to see how we should move forward.

Peter MacKeith, professor of architecture at Washington University, coordinated the Saarinen retrospective, an international exhibit traveling from city to city. Mr. MacKeith also curated a companion exhibit that focused on the process that led to Mr. Saarinen’s masterpiece being built on the St. Louis riverfront — what the Jefferson National Parks Association calls “the improbable dream.”

Mr. MacKeith argues that Arch was not just a matter of genius, but also a matter of process.

A “significant mark on the American landscape was identified and brought forward,” he said, through an “open competition” that reached out internationally. The competition welcomed young architects as well as established masters. The process was unprecedented and has not been replicated since Mr. Saarinen’s design won the competition in 1947.

There is also the matter of Mr. Saarinen’s collaborative creative style, which, in the case of the Arch, involved a team of designers and artists from varying disciplines.

The result, said, Mr. MacKeith, was “a tidal change” in the history of this city and architecture itself, a change that, more than 60 years later, continues to fascinate and awe citizens and visitors from around the world.

Sometime this summer, the Park Service will unveil the final version of a new general management plan for the Gateway Arch, the Old Courthouse and the grounds surrounding both.

Weighing input from thousands of people, the Park Service in March published a “preferred option” proposing an international competition modeled after the 1947 competition that yielded Mr. Saarinen’s winning entry. This time, the competition would focus on how best to connect the park to the public and city of which it is a part while preserving and protecting the Arch’s defining character and iconic image.

If the 1947 competition asked the world’s best designers to imagine what might be done here, the next competition asks them to imagine what more might be done.

Sources say that business leaders here have been lobbying in Washington for legislation that would take part of the planning process away from the Park Service and turn it over to a non-profit organization.

The Danforth Foundation of St. Louis made a similar proposal when it proposed contributing $100 million toward construction of a museum on the Arch grounds.

Civic leaders should spend their energy and resources supporting the Park Service’s design competition. They should back the same kind of independent, open process that helped make the Arch a reality and gave St. Louis one of the world’s great works of public art.

The Park Service could begin moving ahead immediately with temporary improvements to the park’s access while awaiting the results of the competition to begin long-term improvements. Some might be completed by 2015, in time for the 50th anniversary celebration of the Arch’s completion. Others might take longer.

The Arch took 18 years from competition to completion. It was worth the wait. These improvements to the park grounds, too, deserve to be done right.