From 10 a.m.-5 p.m. Saturday, organizers are inviting all of Houston to come enjoy the city’s park. Visitors will see etchings in the paths across the land bridge that tell the story of Memorial Park. Animal footprints also have been stamped into the concrete paths.

Food trucks will be on hand, or guests can bring their own picnics. The festivities include live music and face painting.

On Friday, the city of Houston and Memorial Park Conservancy, gave a sneak preview of the park’s newest amenities.

Major donors Rich and Nancy Kinder, whose $70 million catalyst gift largely funded the project, and Cyvia Wolff, whose $10 million gift paid for the seeding and care of 45 acres of new Gulf Coast native prairie, were on hand as park officials and others, including Houston Mayor Sylvester Turner and U.S. Rep. Sheila Jackson Lee, gathered on top of the tunnels for a ribbon cutting.

In the past 25 years, the Kinders have given $600 million to Houston area nonprofits, with nearly half of it going to park projects, including Discovery Green, Buffalo Bayou Park and Bayou Greenways.

Thomas Woltz, whose Nelson Byrd Woltz landscape architecture firm a decade ago created the Memorial Park master plan that included the Clay Family Eastern Glades in the first phase of work and now the land bridge and prairie in this second phase, called this project his “love letter to Houston.”

Woltz’s team began with thoughts of the 2011 drought that killed a good deal of the park’s tree canopy. Soon after, they pivoted to understand the other extreme with major flooding events that included Hurricane Harvey. 

This weekend, though, his focus is on Memorial Park and the new things Houstonians will enjoy on the 100 acres of the land bridge and prairie.

Woltz described one visit to the park when soil being placed on top of the land bridges was still fresh and raw.

“The soil had just been completed on the eastern mound, and I went for an early morning construction visit and there on the ground were footprints of animals. I had a real emotional response that the ‘build-it-and-they-will-come’ was already working for animals. Animals intuitively knew how to use it,” he said. 

The land bridges were designed for humans and wildlife alike, to make crossing north and south over Memorial Drive safer. The enormous structures made it possible to create more walking/jogging/biking paths, viewing stations and bird blinds for enjoying nature plus lawn space where anyone can sit and enjoy nature.

Sustainability was factored into the project as much as possible, using dirt dug earlier from Hines Lake in the Eastern Glades as well as dirt removed from the wet basin to cover the tunnels and create the land bridge. Some 9,000 cubic yards of the old Memorial Drive — the part returned to park land after traffic was routed through the tunnels — was saved to create a “Scramble” on the north side of the land bridges. There, large slices of street pavement — some with painted lines and traffic reflectors intact — were stacked on top of poured concrete foundations to create an intricate and interesting staircase up one side of the land bridge.

Visitors can simply climb it to get to the top, but anyone there for exercise can run or jump from slab to slab to burn more calories and children can use it for organic play.

Plaques laid into concrete walls atop the land bridge list just some of the wildlife that call the park home. Those animals paw prints were laid into different sections of the walkway to remind visitors that they share the space with four-legged creatures even if they can’t always be seen. 

A late addition to the project was the idea that the tops of the land bridges could be used by those who want to witness sunrise on the equinox and solstice each year.

“In a fractured society, how do we connect people to each other with a sense of community? One way is to create an experience of awe, and that’s a job for landscape architects. Imagine sitting together in the dark on the morning of the summer solstice. That is a moment of awe, and that condition connects us to one another,” Woltz said. “Feeling more connected to society gives me hope for bringing back civility in our society and caring for one another and the places we love, like Memorial Park.”

Dozens of trees — a variety of coastal oaks, Sweet Bay magnolias, red maples, sweetgum, bald cypress and long leaf pines — have been planted across the 100-acre project, some on the slopes or atop the land bridge and others situated near what’s intended to be the wet part of the prairie. A basin was dug 8 feet deep on  the south side of the tunnels, intended to hold storm water as it slowly drains. 

Woltz said it’s deep enough to handle the quantity of rain that fell on the park during Hurricane Harvey, an event that caused significant erosion at the part of Buffalo Bayou that runs through the park. It’s estimated that its bank eroded some 15 feet and soil from the park was found as far away as the Houston Ship Channel.

That resilience was foremost on his mind as his team gathered information on the park’s original ecosystem, Gulf Coast native prairie, and how those plants helped the park centuries ago. The flowers and grasses that make up the prairie develop root systems that can run 12 feet deep, creating a natural sponge to absorb and hold water in a major rain event, and this project includes the creation of 45 acres of prairie.

“It’s interesting, for me, maybe the greatest source of happiness is spending your life building things for people and generations you will never know. There’s something that connects you to the world in a different way,” he said. “There’s something deeply gratifying about that.”

Since this park project began, Woltz’s firm also was hired to design the gardens at the Ismaili Center Houston, Rothko Chapel and, most recently, the academic quad at Rice University.

diane.cowen@houstonchronicle.com