Tiber was born in Bensonhurst, Brooklyn, New York. His family moved to White Lake in Bethel in 1955 where they acquired a rooming house that they expanded into a motel, called the El Monaco Motel, at the intersection of New York Route 17B and New York Route 55 near the southwest shore of White Lake.

Tiber attended Brooklyn College and received a BFA from Hunter College. He was in the MFA program at Pratt Institute.

In his book Taking Woodstock, Tiber says he was present at the Stonewall Riots on June 28, 1969, and that he had a part in bringing the Woodstock Festival to Bethel, New York.

Tiber said he led a closeted life in Bethel in the early 1960s as he spent time managing his parents' El Monaco Motel, serving as President of the Bethel Chamber of Commerce, and, at the same time, participating in the gay scene in New York, where he lived.

According to Taking Woodstock, Tiber read that Wallkill, Orange County, New York had on July 15, 1969 pulled the plug on the planned Woodstock Festival at the Mills Industrial Park northeast of Middletown, New York.

Tiber says in the book that he had a permit for the White Lake Music and Arts Festival, a planned chamber music event at his motel. He contacted Michael Lang and pitched the idea of having the festival on 15-acres along the edge of White Lake by the motel.

According to Taking Woodstock, when Lang said the motel property was too small, he introduced the producers to dairy farmer Max Yasgur, and helped facilitate the deal.

Lang, however, says that Tiber referred him to a local real estate salesman, and that the salesman drove Lang, without Tiber, to Yasgur's farm. Sam Yasgur, son of Max Yasgur, agrees with Lang's version, and says that his mother, who is still alive, says Max did not know Tiber. Artie Kornfeld, a Woodstock organizer, has said he found out about Yasgur’s farm from his own sources.

Tiber left Bethel shortly after Woodstock and soon moved to Los Angeles, where he became a movie set designer. The motel became an Italian restaurant and was torn down in 2004. It is now marked by a clock tower welcoming people to White Lake.

His 1970s book, Rue Haute, was a best seller in Europe, and made into a French-language movie directed by his domestic partner, André Ernotte. It was Belgium's entry for the 49th Academy Awards Best Foreign Language Film in 1977. The book was released in English in the United States in 1977 under the name High Street.

He taught creative writing at New School University, fine art at Hunter College, and art design history at the New York Institute of Technology.