Zodiackillersite.com

I'm not seeing that Mare Island was an independent post. (That doesn't mean it wasn't!)

It's certainly worth confirming where US mail from the base was postmarked in 1969.

Also Treasure Island, which was the naval equivalent of The Presidio, was a possibility for 'San Francisco' post-markage as well.

<The fact that, in at least one case, it can be shown that LE misinterpreted (misread) one of the postmarks as showing - what was it, “JB” instead of “1B” - when sending analysis requests to the FBI, this suggests to me that there is the real chance that they didn’t. Not as to the detail, at least.>

Agreed, it sounds like in that case at least, they didn't understand the coding.

Does Graysmith mention the coding in his book? My guess is that info would have been fed by SFPD. He has an appendix where he describes the postmarks and lists some of the codes, but it's unclear whether he examined or identified the codes.

I have some evidence that Mare Island was NOT in fact post marked San Francisco. I'm working to confirm.

Thanks, these are good finds, but they look like collectors' first covers, where a hand postmark was requested in person. Clearly there was a post office on Mare Island -- but we still want to establish that ordinary mail mailed in freestanding boxes on Mare Island was not typically sent to San Francisco for processing.

Likewise with Treasure Island. Also, it would be good to know how the Presidio base mail worked.

Chaucer wrote:I have some evidence that Mare Island was NOT in fact post marked San Francisco. I'm working to confirm.

My own research appears to be leading to strong doubts as to this possibility, also.

To recap where the idea came from initially, it was noted that the San Francisco Sectional Center Facility processed mail not only for the geographically-located Zip prefixes 940-1,943-4, but also for a further five prefixes, 962-6, as per the following list from the 1969 Postal Directory:



These last five were then identified as corresponding to the following, where 'AP' denotes 'U.S. Armed Forces Pacific' (which I understand to include the Indian Ocean, Oceania and Asia excepting SW Asia):

• 962: AP Military Bases in Korea;
• 963: AP Military Bases in Japan;
• 964: AP Military Bases in the Philippines;
• 965: AP Military Pacific & Antarctic Bases; and
• 966: AP Military Naval/Marine.

It was then wondered whether the last of these, 966, might include domestically-originating naval mail from Mare Island.

Although its hard to pin down a single definitive reference that would settle this, all my investigations to date point to the fact of 'Armed Forces Pacific' being the crucial point. If I am not missing something, the 966 prefix relates to US Naval/Marine operations on deployment in the Pacific, with the arrangement enacted in the "Postal Agreement Between the Post Office Department [USPOD, predecessor to USPS] and the Department of Defense" of March, 1959. This, likewise, would include processing mail originating from vessels through arrangement with the on-board Fleet Post Office (FPO).

It also seems very like that the handling of such mail by San Francisco was processed separately from the regular civilian operation at the Sectional Center Facility, or at least as far as outgoing mail was concerned. This from a 1980 report to Congress on "How Military Postal Service Operations Can Be Improved":

US Comptroller General wrote:The San Francisco Postal Concentration Center is responsible for processing (1) Navy and Marine Corps mail destined to mobile units in the Pacific and shore-based units in South-east Asia, (2) Army and Air Force first class mail from the southern part of the United States, and (3) most SAM [Space-Available Mail] and MOM [Military Official Mail].

The PCC for San Francisco appears to have be located, at the time, at 390 Main Street.

Mare Island appears to have (and to have had) a 945 prefix, and it seems that any mail originating from the base itself would have been processed via this - which, if the list above is not deceiving me, would have been through the Oakland SCF.

On top if this, even as regards the 966 mail, everything seems to point to each vessel having generally installed an FPO on board and hand-cancelling the mail before it leaves the ship. It is my expectation, then, that the postmarks we would be seeing for 'AP Military Naval/Marine' mail in 1969/70 would be of the form of the following earlier examples:

Additional to my previous post, the fact that the actual Naval installation at Mare Island might have been allocated a Zip code prefix outside of the normal way in which these were divided out appears countered by the following, from the "USPS Postal Agreement with the Department of Defense," in which it is specified that:

• C. Postal Service criteria shall be used to assign ZIP Codes to military installations in the United States.
• D. The Department of Defense and the Postal Service agree to cooperate in the assignment and use of overseas ZIP Codes.

The above quotation is, admittedly, taken from a 1980 version of the agreement, but I see no reason to suppose that this wasn't how it worked right from the introduction of the ZIP.

Excellent work Shaq. So do we conclude that a letter mailed in a box on Mare Island in 1969 to a non-military domestic address would have been processed and postmarked in Oakland?

Meanwhile nothing yet from our Rincon Annex expert.

Just to jump back to a possibly important point that Xcaliber brought up a short while ago - that some mailboxes for collection even in 1969/70 and, in particular, those near the main post office, were likely segregated into 'local' and 'out of town' mail at the point of being deposited. The thought then arose whether this may have led to a different processing route, possibly helping to understand the differences in the postmarks on the zodiac letters.

Well, this form of segregation appears to have begun to be introduced nationally, through trials in the first instance, as early as 1954:



In San Francisco, specifically, the introduction was trialled the following year:



Note that the introduction in SF was initially limited just to "the city's financial district."

A further point that jumps out from both extracts is how the aim was to "save an entire Post Office operation" (or "skip a handling step"). So, although this is clearly just a statement about not needing an initial sort from between the two letter types, it still indicates that even before the mail hit Rincon the two were destined for different processing routes. How different - and whether, on Sundays, this could have made the difference between hand- and machine-cancellation - remains the question.

viewtopic.php?f=48&t=1494&p=16893&hilit=Sunday+postmarks#p16893

Per my suspicions, it seems that it is quite possible to drop a letter in a mailbox on a Friday or Saturday and then have it sorted, processed, and postmarked on Sunday.