Estero Llano Grande State Park is celebrating its 20th anniversary this year.

Nestled in the Rio Grande Valley, the park covers 230 acres and draws visitors from across the region.

Weslaco resident Amparo Garza is one of them. She often visits and has watched the park grow over the years.

"All the different types of birds, different bugs, well we got to see the alligator, we got to see the baby alligator today," Garza said.

She said the park has improved a lot since her early visits.

"They did a lot of the little walking trails, so it's not so muddy now, and we got lots of shades and lots of benches," Garza said.

Estero Llano Grande State Park Superintendent Javier De Leon has seen the transformation firsthand. He volunteered at the park before it opened in 2006.

"It's a combination of several different tracts of land. Where we're standing right now was a bare dirt farm field, so it's a big transformation to what it is today over the last 20 years," De Leon said. "But ever since our wetlands came in, we've been a huge hot spot for bird watchers all over the country."

De Leon says around 30,000 people visit the park every year, including 2,000 students through field trips.

For many children, it is their first time seeing a native bird or tree. De Leon says those experiences often inspire visitors.

"They see all these butterflies here in the park, you know, I want to plant a butterfly garden at home, so it's really, we're growing stewards. I think that's the biggest thing we've done in the last 20 years," De Leon said.

The park has also documented 340 bird species. De Leon says the team works to preserve the land as naturally as possible through every season.

"We try to keep an eye on it but at the same time we try to preserve it as natural as possible," De Leon said.

Different activities will take place this summer to mark the milestone. The official 20 anniversary ceremony is in November.

Watch the video above for the full story.