For more than 20 years, the artist Christo has worked tirelessly and spent $15 million of his own money to create a vast public artwork in Colorado that would draw thousands of tourists and rival the ambition of “The Gates,” the saffron transformation of Central Park that made him and Jeanne-Claude, his collaborator and wife, two of the most talked-about artists of their generation.

But Christo said this week that he had decided to walk away from the Colorado project — a silvery canopy suspended temporarily over 42 miles of the Arkansas River — because the terrain, federally owned, has a new landlord he refuses to have anything to do with: President Trump.

His decision is by far the most visible — and costly — protest of the new administration from within the art world, whose dependence on ultra-wealthy and sometimes politically conservative collectors has tended to inhibit galleries, museums and artists from the kind of full-throated public disavowal of Mr. Trump expressed by some other segments of the creative world. Last week, the artist Richard Prince fired an opening salvo, returning a $36,000 payment for an artwork depicting Ivanka Trump, the president’s daughter, owned by her family…

“I use my own money and my own work and my own plans because I like to be totally free. And here now, the federal government is our landlord. They own the land. I can’t do a project that benefits this landlord.”

Asked to elaborate on his views of the new president, he said only, “The decision speaks for itself.” He added, “My decision process was that, like many others, I never believed that Trump would be elected.”