Donald Trump and Mike Pence have vowed to “repeal every single Obama executive order” on their first day in office, and if they do, the National Park Service status of the Waco Mammoth National Monument would be in jeopardy.

President Barack Obama signed an executive order on July 10, 2015 that designated the site as a National Monument after a years-long effort to pass legislation adding the site to the park service failed in Congress.

Under the 1906 Antiquities Act the president bypassed Congress and issued the executive order for the designation.

U.S. Rep. Bill Flores, R-Bryan, who was elected to a fourth term on Tuesday, supported the designation, but at the time called the use of the Antiquities Act to enact it “controversial.”

He said Wednesday that Trump also opposes use of the act “to take large swaths of land and put them into a park without the consent of Congress.”

Should Trump reverse Obama’s order, Flores said he would go through the necessary steps to restore the National Park Service designation.

Since the monument was established, the number of visitors to the site has quadrupled.

Waco City Manager Dale Fissler said the designation has" been a huge win for the park service and the city."

The site, which has attracted researchers from around the world, was discovered more than 30 years ago, and contains the largest known concentration of mammoths that died in a single event.

A painstaking excavation of the site has uncovered the remains of 25 Columbian mammoths that died nearly 68,000 years ago, probably after they were caught in a flash flood.

In 2002, then U.S. Rep. Chet Edwards, D-Waco authored legislation which later became a law that directed the National Park Service to determine the feasibility of establishing a national park at the Waco Mammoth Site.

Three years later he secured $200,000 for preservation efforts at the site and an additional $200,000 for the Baylor Mayborn Museum's Mammoth Exhibit.

In March 2009 the U.S. Department of the Interior recommended including the site as part of the National Park Service, and Edwards introduced the “Waco Mammoth National Monument Establishment Act of 2009,” which would have implemented the Department of Interior proposal and authorized appropriations for the project.

The original U.S. Department of the Interior recommendation called for giving the Park Service the lead responsibility for protection, scientific study and visitor enjoyment of the site in partnership with the City of Waco and Baylor University, which was the option local leaders preferred.

The House passed the bill, but the measure later died in the U.S. Senate, the victim of a maneuver called an anonymous hold.

Subsequent measures introduced by Edwards’ successor, U.S. Rep. Bill Flores, R-Bryan, called for designating the site as a National Monument.

The new bill didn’t provide funding for the monument, but the authors said local support would make the national recognition possible without additional federal spending.

Ground was broken in 2008 for $3.2 million visitor center and pavilion to protect the site, which has been operated since 2009 by the city in partnership with Baylor University and support from the nonprofit Waco Mammoth Foundation.

In April 2015 National Park Service Director Jon Jarvis toured the site and later said he would ask the Interior Department to seek Mr. Obama’s approval to designate the site a national monument.

Two weeks later the Waco City Council voted to turn five acres of the site and the excavated remains over to the federal government, leaving just more than 100 acres as city property, but as administrative land in the national park system.