Hal,
"John Lindley Higham created this map (18" x 26"), known as the MAP OF THE LOST DUTCHMAN GOLD MINE AREA for "the purpose of an advertising medium for the advancement of publicity of the book entitled...".
In 1957, Higham sold the rights to this map to one Thelma Hubbard. It was a twenty year contract granting Hubbard the right to "print, use, reprint and sell, in the State of Arizona,... in any quantity, for the consideration of One Hundred Dollars ($100.00)."
There was also a poem attached to this agreement entitled "The Arizona Key Bird".
It's nice to see you continuing to do the basic research. My research of Highham and Barnard is limited, so it is not surprising that I was unaware of the document you are referencing. Interesting. Thanks for sharing.
I would only suggest that when you uncover this kind information you include the source. Otherwise the infomation can well be lost among the stories and unfounded specualtion that we usually see on the forums.
A simple reference like, Maricopa Deed Records website. Search on John Higham. We can then review the actual document.
I see you are also researching the Peralta Stones and I suspect we are at least 170 degrees apart on the story but you seem to be moving in my direction a bit. Of couse most people realize that I believe that Tumlinson made the stone carvings and we can reasonably trace them to the late 1940's and Travis. There are a lot of documents and family stories that support this conclusion and (In My Not So Humble Opinion

) no one has presented any documentation that would push the stones into an earlier time period.
Our area of agreement appears to be that the maps are modern and they depict a lot of treasure symbols as opposed geological features. This is only a general statment and there may be a few geological features represented also. Couple of rivers and mountin areas?
Keep after the basic research. Thanks!
Garry