Biber died in Pueblo, where he had been hospitalized for complications from pneumonia. The cause of death was not announced Tuesday.
"We've lost a tremendous friend in our community," said Mary Winter, owner of the Cormi Funeral Home in Trinidad, a town of 9,300 near the Colorado-New Mexico border.
Winter said Monday that Biber was her family's doctor for generations. "He was just a great man," she said. She said no public services had been scheduled.
Biber, an Iowa native, moved to Trinidad in 1954 after serving as an Army surgeon in South Korea. As the town's only general surgeon, he delivered babies, removed appendixes and performed other more routine operations.
He told The Associated Press in a 2000 interview that he performed his first sex-change operation in 1969. A social worker he had met through a welfare case asked for the surgery, and he agreed after talking to a New York physician who had done some sex reassignment operations, and getting sketches from Johns Hopkins University.
Word spread, and at one point he was performing 150 transsexual operations a year, he said.
He stopped doing surgery in 2003 and closed his practice in 2004, at age 81, saying insurers refused to renew his malpractice coverage. He said the companies gave no reason but he suspected it was because of his age.
Biber was a former Las Animas County commissioner and also had a small ranch east of Trinidad.
Residents of Trinidad have said the town was largely accepting of Biber's sex change practice. Former Trinidad Mayor Harry Sayre said in 2004 that Biber was a pillar of the community.
"I consider him probably one of the outstanding leaders in Trinidad of the last century," Sayre said. "He and I had our battles many years ago, but I consider him a real true friend."
Biber's protege, Dr. Marci Bowers, underwent a sex-change operation several years ago and now performs an average of five such operations a week in Trinidad.
"I think he put the operation on the world map," Bowers said. "He made it safe, reproducible and functional and he brought happiness to an awful lot of people. And when you wanted a voice of reason, he was always there."