As the Trump administration plans for a border wall, many residents in the Rio Grande Valley are concerned about what that means for areas on the other side of the barrier, including ecologically sensitive and historically significant land.

This past weekend, anti-border wall protesters took to the streets to try to stop the wall.

It's 7 a.m. on Saturday at the Our Lady of Guadalupe Church in Mission, Texas. With signs and bullhorns, several hundred gathered for a four-mile march to La Lomita Chapel.

“La Lomita is the mission site that Mission Texas got its name from. It’s one of the first Spanish Missions," says Scott Nicol, who leads the Sierra Club's Borderlands campaign. "It’s got a historic chapel on its site and it stands between the levee and the river in a place where they want to turn that levee into a border wall.”

Nicol is trying to raise awareness that the border wall would isolate significant areas along the Rio Grande that he calls a "no man’s land."

“The historic chapel would be in the no man’s land the same way the Santa Ana National Wildlife Refuge and the butterfly center and hundreds of peoples' private farm land would be in the no man’s land,” says Nicol.

As the procession made it way through the street, chants of “No border wall” gave cadence.

This is the first major protest in Texas against the border wall since the presidential election of Donald Trump, which he won with the help of a chant of his own: “Build that wall."

Trump and his supporters say the wall would be a way to stop illegal immigration and secure the nation’s southern border against the flow of illegal drugs and terrorists.

Marchers like Shanna Lee from Austin say they support national security, but a border wall isn’t a solution.

“They already have border patrol and it’s not going to stop someone from coming in illegally. There’s always a way,” she says.

Lee made the trip down from Austin to take part in the protest. She admits this march is unlikely to change the minds of many who support a border wall.

“We have to show that there is an opposition to it and making our voice heard," Lee says. "So it’s worth coming out here for this demonstration and show that we’re not just going to take this lying down.”

After almost two hours walking in the heavy, humid summer air, the procession reached its destination – La Lomita Chapel, only a few hundred feet from the banks of the Rio Grande.

The real fight to stop the border wall isn’t going to be here in South Texas, but in Washington, D.C., and in the halls of Congress.

Congressman Vicente Gonzalez is a Democrat who represents the 15th District of Texas, which reaches from McAllen to Seguin. He says the $25 billion price tag for the wall should be an issue.

“I’m all for law and order on the border, I just don’t believe that a brick and mortar wall will secure us," Gonzalez says. "I think we should be talking about technology like aerostats, cameras, sensors, and use our resources more intelligently. It’s just a monumental waste of tax payer dollars.”

Republican Texas Senator John Cornyn recently proposed a similar compromise measure that includes some wall, instead of a continuous wall from Brownsville to San Diego, like Trump has called for.

“It’s super destructive and super violent," says Olivia Mena, a professor of Mexican-American studies at UT Austin. Mena recently completed a book looking at the growth of border walls around the world. She says this is a global trend, driven by an oversimplified notion of what a border is.

“People think borders are hard and ridged and firm, and the divisions of inside and outside are extremely sharp and visible," Mena says. "We know as border residents that lines of belonging aren’t that sharp and clear."

What is clear is that the people of South Texas who will have to live with the impact of the border wall are asking to be heard in the political process.