The Iowa state Capitol is 1.6 miles from Meredith Corp.’s downtown campus.

I measured the distance recently to get a feel for how Des Moines has changed in the three decades since the Des Moines Vision Plan was created.

Most of the changes suggested by the 1991 Vision Plan have occurred in and around that 1.6-mile line, where the goal was to create a 21st-century urban environment.

The first target was the western entrance to downtown, where completion of the John and Mary Pappajohn Sculpture Park in 2009 created a new gateway that instantly became an integral part of the city’s identity.

Other sites included the downtown riverfront, the East Village and Court Avenue business districts, and the Martin Luther King Jr. Parkway bypass south of downtown. Development in those areas produced an explosion of housing and a return of retail to the urban core.

I’ve been thinking about those changes as I collaborate with New York architect Mario Gandelsonas on a book explaining where the Vision Plan’s concepts came from and how they became reality.

Gandelsonas is the founding father of the plan. He teaches at Princeton University, too.

My part of the collaboration is to tell how Des Moines leaders banded together in the 1990s and early 2000s to implement the Vision Plan. As a reporter, I covered the early planning and much of the development that followed.

Looking back, I’m struck by how fluid and open the process was. Powerful public and private interests frequently butted heads but were able to resolve most differences. Much of the credit goes to the open-mindedness of business leaders, including Jim Cownie, Bill Knapp, the Ruan family, Meredith Corp.’s Jack Rehm, Principal Financial Group’s David Hurd and Barry Griswell, and builder Fred Weitz, among others.

My current focus is on Western Gateway Park, and how it evolved from a collection of auto-repair shops, low-end taverns and pornography outlets to become one of the world’s premier sculpture gardens.

In retrospect, it’s worth noting that while the park was still developing, two competing concepts could easily have sent things in other directions.

One involved removing all buildings from the six blocks east of Meredith and creating underground parking beneath the park.

That idea was challenged in 1996 by California consultants, who said it would be more efficient to develop the space as a “commons area,” leaving a few significant buildings and eliminating underground parking.

Ultimately, that concept won out. Three older buildings were retained and two new public buildings – a downtown library and an education center – were added.

If six blocks of underground parking sounded like a reach, imagine what a 20-story, domed rainforest would have looked like. That’s what Ted Townsend, a somewhat eccentric businessman, proposed in 1997.

Townsend wanted to build the rainforest and related attractions on six blocks south of the proposed Gateway Park.

Initially, he won support from others – most notably Charles Johnson, the chief executive of Pioneer Hi-Bred International and chairman of the local Chamber of Commerce.

Support faded when it became apparent that there was no clear funding source for Townsend’s $330 million idea.

Over time, the sculpture garden, the riverwalk, Court Avenue, the East Village and the MLK bypass created significant links between the Capitol and Meredith.

A few years back, Gandelsonas proposed another link that would connect the 1.6 miles between the Capitol and Meredith with a series of greenhouses that could produce local food year-round and provide space for agricultural research.

That idea, like the Pappajohn Sculpture Garden, would attract worldwide attention, but it remains for now on a back burner.