PUNTA GORDA — To find a pastime after retiring to Punta Gorda 25 years ago, Chet Lewis volunteered at what was then just a vision for the Charlotte Harbor Environmental Center.

Lewis blazed the center’s first trails. He became a nature instructor for kids on field trips. He skippered the center’s first boat trip to guide visitors on wading expeditions. And he now mows the trails with a rider.

“You name it, I’ve done it,” he said Saturday at an event to celebrate CHEC’s 25th anniversary.

“It reminds me I’m getting old,” he said of the milestone. He added, however, his toils have been rewarded.

“What tickles me is when a fourth-grader from way back comes back and takes his parents to visit the center,” he said.

Lewis was one of ­perhaps 100 area residents who participated in the event. They strolled nature trails, listened to talks from authors, including naturalist Charles Sobczak, and watched slide presentations about the many critters of the estuary.

Then, they lunched on roasted pig, smoked mullet and swamp ­cabbage provided by Peace River Seafood, while listening to folk music by Michael Haymans’ Hibiscus Band.

The center was ­established in 1987 under a partnership among the Peace River chapter of the Audubon Society, the Punta Gorda City Council, the Charlotte County Commission and the Charlotte County School Board. CHEC acquired its 830-acre Alligator Creek Preserve off Burnt Store Road. It later acquired a second site, Cedar Point Preserve in Englewood.

Its mission is to raise appreciation of the Charlotte Harbor ecosystem.

Estuaries contain the “most productive habitats on Earth,” said CHEC naturalist Cindy Christel. She pointed out that 80 percent of fish rely on estuaries.

Christel pointed out the harbor was once so healthy, its massive schools of fish would attract so many birds they’d “black out the sun.” She contrasted that picture with the algae-choked water from Lake Okeechobee. “It’s like pea soup,” she said.

“It shows you how important wetlands are,” she said. “They’re the kidneys of the land.”

Several visitors said they’ve hiked the center’s trails in the past.

“I had the day off from work, so we figured it would be nice to get outside,” said Mike Meli of Port Charlotte, who was hiking about during the event with wife Kate and kids, Alyssa and Mikaila.

Those celebrating the milestone included Steve Osborne, a former General Development scientist who was an Audubon member back when the idea for the center first surfaced. He said he was pleased to know the center has expanded awareness, but hopes to see it reach more people in the future.

The center plays host to some 16,000 visitors per year. They include a thousand fourth-graders who participate as part of their curriculums, said Lee Swift, a School Board member who has sat on CHEC’s board since its inception.

“There’s lots of kids that have never walked out in the woods,” he said. “They enjoy it and learn a lot — and we’re proud to be a part of that.”

CHEC’s board recently met to refocus the center’s mission. Dorothea Zysko, president, said she hopes to expand CHEC’s learning programs to city parks.

Another priority calls for CHEC to “reach out to Mote (Marine Laboratory) and form a partnership,” said Jim Thomson, CHEC’s executive director.

“Mote is going to bring a concentration of researchers and funding that has never been here before,” Swift added.

Email: gmartin@sun-herald.com