I’ve enjoyed buying a number of vintage maps like AAA from 1977-1982.  Evidence that actual map contures were used is suggested in the shape of the tail in image 4.  More localized maps such as tourism or park maps were readily available at transit hubs or visitors centers.

Didn’t have to be Google Maps.  Terraserver was active as early as 1997.  I remember making a composite photo from online sat imagery around 2001 or 2002.

Seems really doubtful…
Byron Preiss (11 April 1953 – July 9, 2005)
Google Maps was first announced on the Google Blog on February 8, 2005,
Of course it was useable in beta the original resolution was awful compared to whats out there today
October is really when it went live.

kinda makes me wonder if Preiss looked over the treasure spots with google and detemined them still findable.

The “pirates” can no longer say “We Lost Our Gold”.
Gold Dug Up and Given to Charity
http://cityroom.blogs.nytimes.com/2012/ … ater-good/
The huricane destroyed physical markers, making the clues invalid.
http://welostourgold.com/thehuntbeover/
And so another hunt has been brought to an end, not by being found or won, but because the setters had to dig up the prize and cancel the contest.  At least NYC will benefit, and the players get closure.
It is a sobering reminder of what a mere 2-3 years can do to a buried treasure hunt, when nature attacks.