Ross Brady, a long-standing member of AAL, says:

In the mid-60s the University of New England (UNE) was a centre of Logic for Australia, essentially due to the presence of Len Goddard and Richard Routley. A logic conference was held there in 1964, attended by 25 people, and after this conference a meeting of 18 of those people occurred, to discuss the setting up of a logic association. Such a motion was passed, to be ratified at the next meeting. The inaugural conference was held in 1965 at UNE, with Len Goddard as President and Richard Routley as Secretary. At the AGM, the ratification took place, initiating the Australasian Association for Logic (AAL).

For more of Ross' tale, including a complete list of AAL conferences, click here.

And: the original documents for the 1964 meeting and the 1965 meeting.