Katie Lee, a free-spirited folk singer who found her mission as a performer and writer protesting the loss of Glen Canyon’s spectacular beauty to a dam on the Colorado River, died on Nov. 1 at her home in Jerome, Ariz. She was 98.

Her death was confirmed by Kathleen Williamson, the executor of her will.

“Rivers are the lifeblood of our planet and they need to flow,” Ms. Lee said in “Kickass Katie Lee” (2016), a short biographical film by Beth and George Gage. “They don’t need to be dammed every 15 feet.”

Eloquent and blissfully profane, Ms. Lee joined conservationists like David Brower, executive director of the Sierra Club, and the writer Edward Abbey to try to stop construction of the 710-foot-high Glen Canyon Dam in Northern Arizona, which opened in 1963. She became part of the chorus of environmentalists that ever since has demanded that the canyon be restored.

The only impediment to her blowing up the dam, she would say, was that she did not know how.

Her enchantment with Glen Canyon began in 1953 during a visit with friends and continued when she became a river runner. She adored its rapids, and the breezes that she said sounded like voices speaking to her. She swam nude in its potholes and waterfalls. She explored its 125 contoured side canyons, each of them named (some by her), and each one a different aesthetic experience.