It was founded by Paul Williams, Chester Anderson, David G. Hartwell, and Joel Hack.
Entwistle published poetry and nonfiction books by Williams, and novels by the likes of Philip K. Dick, Anderson, Tom Carson, and others.
Although formed around 1968, the first book Entwhistle published was Williams's Time Between, "a hippie journal in the communes and on the road, December 1969–February 1970," published in 1972.
At that point, Entwhistle was based in New York City.
The company was based in Glen Ellen, California (north of San Francisco) from 1976 to 1994, and then moved to Encinitas, California (north of San Diego).