On April 19, 1966, John Keel visited the Pentagon, to interview Lt. Col. Maston Jacks of Project Bluebook for his projected Playboy
article. They talked for two hours. John later wrote a report of the meeting, and sent copies to NICAP, APRO, Ivan Sanderson, and his editors at Playboy
. I posted Jacks's response to John's initial letter of inquiry here
, as well as Sanderson's response to the report; I hadn't found this report yet. John also describes a preliminary visit to NICAP, including a meeting with Major Donald Keyhoe.
The report is six pages; below are the first two. More to come!
P.S.: As William Grabowski mentions in the comments, John gives a short version of his interview with Jacks in The Mothman Prophecies
. It's on page 23 of the Tor edition.