Less than two decades ago, land around the Lehigh Gap Nature Center was barren and lifeless.

Not even a blade of grass could be found on the mountain; anything that had grown there was snuffed out by 80 years of pollution from the nearby Palmerton zinc smelting plant.

Dan Kunkle likened its appearance to a moonscape.

“Not only was there nothing, the soil was sterile. There weren’t even microbes in the soil because of the metal contamination,” said Kunkle, the center’s executive director emeritus.

But a handful of individuals never gave up on a dream to restore the land and bring back its natural beauty.

It was a grand dream, one that Kunkle called “doing the impossible” when he pitched the plans to federal lawmakers.

Last week, the center celebrated its 20th anniversary with a tour of the now-flourishing grounds and a ceremony to honor those who’ve been involved along the way. Kunkle said no one could have ever imagined a Superfund site like this one would one day turn into a nature refuge.

“This used to be bare rock and now it’s green. It’s getting better all the time,” Kunkle said while standing on a trail about a mile from the visitors’ center in Slatington.

As he spoke, birds chirped, butterflies explored and several hikers passed by.

Not so long ago, the only species that would grow on the polluted land was sandwort. It was planted on test sites in early 2003, and by fall, it had sprouted.

“We have some of that around,” he said. “That accumulated zinc at approximately 14,000 parts per million.”

While on the trail, Kunkle pointed toward the site of the former New Jersey Zinc Company. The company closed in 1980 and has since been torn down.

“The smoke blew over this, and it was the smoke that dropped the pollution,” Kunkle said. “I had a lot of people come here saying this place was mined but this was all from air pollution.”

Former state Rep. Keith McCall, who supported the center’s efforts, remembered the thickness of the smoke.

It was so dense at times, he said, that motorists traveling on Route 248 would flick on their headlights during the day in order to see.

Kunkle said the company didn’t intentionally pollute the area.

“It was a very responsible company. They had the best pollution controls over those years,” he said.

Despite the efforts, the entire ecosystem had collapsed by 1950.

And in 1983, a 3,000-acre area was declared a Superfund site. The zinc company, Kunkle said, attempted to restore the area but its efforts were fruitless.

Kunkle said the center eventually purchased 756 acres of the decimated land, and decided to plant native, warm-season grasses like sandwort. It would take some time.

Some seeds were hand sown, and others were dropped from helicopters and planes.

Eventually, they began to sprout.

“Those grasses are a plant that have a tremendous root system and they build soil,” he noted. “The roots can go 12 to 14 feet underground – and they grow on almost anything.”

With the grasses came shrubs and trees.

Sherry Acevedo, with the Delaware and Lehigh National Heritage Corridor, recalled overseeing Lehigh County juvenile probation students on the steep, rocky mountain. The students carried backpacks full of seeds that they sowed by hand.

“If you’ve ever been to Boulder Field at Hickory Run State Park, this was very similar to Boulder Field,” she said.

Acevedo said the youths questioned how the seeds would germinate under such barren conditions.

“They would say, “Ma’am, this is a waste of time,’” she recalled.

Eventually, butterfly bushes, milkweed and wildflowers took hold in the grass the students and others planted.

The area also has the commonwealth’s largest indigenous population of wild bleeding hearts. The plant is endangered, noted Chad Schwartz, the center’s executive director.

Following the tour, the group returned to the Osprey House visitor center in Slatington.

An old farm house, the property has been expanded to include classroom learning space, laboratory and library.

Outside, there’s a sensory garden planted with native species like golden rod, sweet fern, mountain mint and phlox.

There’s a pond, pavilions and a starting point for some of the center’s 13 miles of trails.

Partners, sponsors, donors, volunteers and board members gathered on the center’s wide porch to enjoy lunch.

At one point, a bald eagle landed on an overhead power line.

“That’s serendipity,” one guest said.

Kunkle and Schwartz chatted with state Sen. David G. Argall and state Rep. Doyle Heffley on a side deck that overlooks the Lehigh River.

Argall noted that he was a Boy Scout leader in the 1980s and would take Scouts hiking on the Appalachian Trail near Palmerton.

“The kids said, ‘What happened here?’” he said of the barren land. “They thought maybe there was a fire and I had to explain to them that it was much, much worse.”

He presented Kunkle and Schwartz with a congratulatory proclamation from the state Senate.

“You literally have turned a moonscape into something that we can all be proud of. This isn’t just a local success story, this is a national success story,” Argall said. In fact, it is the only Superfund site in the nation that has been transformed into a nature center.

Heffley thanked Kunkle and Schwartz for their hard work. He recalled traveling on Route 248 and seeing the zinc company on one side and the bare mountain on the other.

“As you look out here now, who would have thought we would be seeing so much green?” Heffley said.

He presented a congratulatory citation from the state House of Representatives, and said he hoped to be on hand for the 50th anniversary.

Kunkle thanked the state lawmakers for the special awards.

“But really nature gets the credit,” he said. “What we did was we helped nature heal itself. It did the job. That was our whole attitude for the project: help nature heal itself.”

During the ceremony, Kunkle recognized all supporters and partners. Each had the opportunity to speak.

“So many people have been involved in this place as our partners, our sponsors, our donors, our members,” he said.

Dr. Diane Husic, president of the center’s board, spoke about the restoration efforts, calling them a “miracle.”

The area, she said, now supports a vast array of wildlife from plants to pollinators to mammals.

Bob Hoopes, retired board member, reflected on the center’s early years, and Schwartz recognized volunteers.

Another celebration is planned for the summer.