MISSION--Every Fall Monarch butterflies grace the Rio Grande Valley in vast numbers. Before they reach their destination in Michoacan, Mexico, they visit just in time for another butterfly season.

On Saturday, the 22nd annual Texas Butterfly Festival held at the National Butterfly Center (NBC) in Mission brought hundreds of visitors from the Valley and around the globe wishing to spot some of the over 170 butterfly species present around gardens of the NBC. Children wearing butterfly wings and face paint blended in with the unique creatures.

Though, unless you’re from the Valley, you might not be used to seeing so many butterflies in November.

“If you want to see butterflies all year long, this is the place to come,” said Dr. Jeffrey Glasberg, president of the North American Butterfly Association. “If you go anywhere else in the country right now, you would hardly see any.”

Glasberg founded the NBC in 2004, on what used to be an onion field on the banks of the Rio Grande. Now it is a nationally recognized nature park that brings hundreds of birders and butterfly watchers to the area from across the globe.

One of those visitors is Steve Moore, a member of NABA and resident of Massachusetts, who has spent five weeks in Mission every year since 2010 for the sole purpose of spotting butterflies he can’t find anywhere else.

Like the butterflies, him and hundreds of other naturalists spend most of the month wandering through the Valley’s nature parks.

“The first year we came down my kids were concerned about us spending Thanksgiving alone. Turns out we had Thanksgiving dinner with 45 other butterfly watchers,” Moore said, before scurrying to catch a glimpse of a Red Rim butterfly. “You never know what you’re going to see here; you could spend years looking for that one.”

Unfortunately, the fate of the NBC, and subsequently the butterflies, is uncertain.

In July, the Executive Director of the NBC, Marianna T. Wright, saw a construction crew hired by the Department of Homeland Security surveying and clearing land on the privately owned property without notice.

One of president Donald Trump’s central campaign promises is a border wall. Though logistics and funding for the project have not been finalized, Wright feels it is an imminent danger to the nature parks across the Valley.

“I don’t see it as a threat; I see it as a promise,” she said.

Unlike other nature parks at risk of being penetrated by the wall, the NBC is private property owned by the NABA. On Oct. 4 the NABA board of directors authorized a notice of intent with the federal government. If there is no response by 60 days they plan on suing.

Ultimately, the U.S. government has the right to eminent domain, meaning they can seize private property for just compensation with due process.

If built, the wall would sit on the levee, cutting off 1.2 miles of the facility. It is currently the largest botanical garden in the U.S. focusing on native plants, with several projects underway south of the levee.

“If the wildlife that lives here cannot cross to range, forage or breed, I don’t know what will happen,” Wright said. “If you were a business and you lost two thirds of your store, what would happen to that business?”