Margaret Montaño from San Luis, Colorado, stands outside the Colorado Supreme Court and Court of Appeals building in downtown Denver. 

(Nathaniel Minor/CPR News)

More than a hundred southern Colorado residents filled a courtroom in downtown Denver Wednesday, where they heard the latest round of arguments in a long-running legal battle over who can use a privately owned historic ranch in the San Luis Valley.

The Cielo Vista Ranch's new owner, a Texas billionaire named William Harrison, is appealing the implementation of two state Supreme Court rulings from 15 years ago that give some local landowners access for things like gathering wood and grazing livestock.

Ronald Fano, an attorney representing Harrison, told a three-judge panel with the Colorado Court of Appeals that those landowners were "granted unregulated rights to take and use the natural resources of the privately owned ranch." 

Fano made clear his client is not challenging the Supreme Court's rulings, but rather a trial court's implementation of them. He said nearly 5,000 local landowners now have access, though Shirley Romero-Otero, president of the Land Rights Council in San Luis, said that number is under 1,000 

The hearing Wednesday was just the latest in the case that began in 1981. Craig Welling, one of the three judges hearing the case, noted the overflow crowd and said it signified just how important the case has been to San Luis Valley residents — and the attorneys who've argued it. 

"Quite a few lawyers have spent a considerable portion of their career on this case," Welling said. 

Andres Montoya, a Costilla County resident, said brought his children and grandchildren up to Denver for the hearing.

"I want them to be aware that this is something very important that they have to support," he said. 

He vowed to fight the case until "the day he dies." Then, he said, he hopes his kids will keep the battle going.