Although often mentioned as a great porn director, his work as a director isn't always that great - from his fantastic first effort L.A. Plays Itself to the abysmyl late 80's Breaker Blue (his last film?) - the quality of his directorial work varies greatly. But he was also a porn star; and unlike other porn stars, he could direct successfully, act (fantastic in El Paso Wrecking, not so good in his own A Night at Halsted's), and he did some amazing cinematography, primarily in his lover Joey Yale's films, like Trick Time.
From California, he did gardening work as a young man (rumored to be Vincent Price's gardener!) and met Joey Yale when he was working on his first film (Joey is featured in L.A. Plays Itself). While much of the 70's, and very early 80's gay porn films were NY centered, Halsted )along with William Higgins) focused more on the blond, skinny California type (his personal taste). By the mid 70's, Halsted and Yale formed the production Company COSCO, trying to gain more control over their work (and its revenue!). COSCO produced many films in the late 70's through mid 80's (usually distributed thru VCA, and HIS), as well as numerous magazines, like Package and the many associated with their Cosco films.
The sidebar on the left will direct you to the films he's worked on, a favorite soundtrack listing from A Night At Halsted's, as well as an interview with him and his lover Joey.