This always was a really interesting thread. I don't know that anyone has ever actually tried to pin down precisely when the DA came into existence or whose idea it was, although there sure have been a number of stories about it, but so far this thread has not exactly done that, in my opinion. To do that I think the first order of business would be to pin down as accurately as possible the precise date that photograph that appears in Posts #3, 322, and 341 was taken, and even if that could be done it may not answer the question (particularly if it was taken after Jan, 1918).
However, the first photograph showing the hole without the DA was very likely 1914 or not later than early 1915. There are a number of supporting reasons that show up in that photo that have to do with the chronology of the construction of the course to assume or conclude that.
Also, even though the angles or vantage points from where the various photos on this thread of this hole were taken from are not all that helpful for comparative purposes, the following should certainly be included in the comparative analysis anyway.
After Crump died (Jan 1918) not much was done to the course architecturally for the next two years other than a massive program to fix the agronomy and the completion of holes #12-#15 to bring them into play (the course was originally opened for play with eleven holes in play and following that for approximately 4-5 years only fourteen holes were in play. All eighteen holes did not come into play until the summer of 1920 and even with that some bunkering on the #12-#15 stretch was not done).
In the fall of 1920 Hugh Alison came to Pine Valley and on January 8, 1921 he offered a hole by hole improvement plan. The Committee voted on every itemized suggestion Alison made as to whether it was approved, put on hold or not approved.
Alison's only suggestion for hole #10 was thus:
"It is suggested that the banks which partly hiade (sic) the bunkers in front of the green, should be removed."
The Committee approved this suggestion on March 13th and 14th 1921 and notated the following regarding it:
"Remove banks in front of the bunker at face of green."
One can also notice from some of the photos as well as familiarity with the hole itself that the ground from the tee to near the green, particularly on the right was once higher than it is now. Apparently that difference was the execution of Alison's 1921 suggestion.