Texas naturalists also see a border wall as a threat

MISSION, Texas — The specter of a border wall has loomed over the Rio Grande Valley since 2006, when President George W. Bush signed the Secure Fence Act authorizing 700 miles of fencing along certain stretches of the southern border. But the election of President Donald Trump, who made completing the wall a centerpiece of his campaign, has spurred renewed concern about the economic and environmental consequences of such a wall.

Although Congress has yet to provide the money for Trump’s wall, preparations for its construction are underway. Officials with Customs and Border Protection recently held a meeting in the valley at which they displayed a map of the wall’s proposed route.

When asked about the map, officials emphasized that it was only a proposal, and that the wall’s construction was dependent upon the federal budget for 2018.

But that does not mean that the officials tasked with building the wall cannot start making plans.

Because of the anticipated resistance from private landowners, the first sections of the border wall most likely will be built on federal land. In the valley, that includes the Santa Ana National Wildlife Refuge near the city of Alamo, where officials and contractors have been taking soil samples.

Known as the crown jewel of the national system, the lush, 2,088-acre refuge was established in 1943 and is one of the most popular bird-watching destinations in the country, attracting about 165,000 visitors a year.

The threat to the area’s natural habitats like the birdlands and butterfly haven has prompted letters to members of Congress, lawsuits and protests — the most recent of which was Saturday in this remote south Texas city in the Rio Grande Valley.

The Rio Grande Valley is one of the most biologically diverse regions of the country. It is a major bird migration corridor, with more than 500 species, more than half the total number in North America. It is also the last remaining habitat for the endangered ocelot, a medium-size spotted cat hunted nearly to extinction for its fur.