Deep Throat: A 1992 Atlantic Article Speculates on Mark Felt

As I said at the outset, I didn't know who Deep Throat was. I know from conversation with Bob Woodward at the time only that he was from the FBI.
He could well have been Mark Felt, who admitted that he harbored ambitions to be the FBI director -- not only at the time of Hoover's death but also in the spring of 1973, when Gray's nomination as permanent director failed to win confirmation and Nixon named William Ruckelshaus acting director. Felt was known in Washington as a person willing to talk to the press. He has denied that he was Deep Throat. "I never leaked information to Woodward and Bernstein or to anyone else!" he wrote in his 1979 book. Felt retired from the FBI in 1973, not long after Ruckelshaus's appointment.