Travis,
Yes it is just a theory, and it is all mine, so you can take it or leave it as you wish.
I will start at the beginning just the way I explained it to Paul in another discussion, and you will see how my theory developed. When I first came to AZ and started getting into heavy research. I spent a lot of time in the Historical Library at the State Capitol, and the main Phoenix library searching for anything I could find that pertained to the 1880's time period. Eventually I worked my way into the old newspaper archives. The stories that kept showing up that caught my interest, as something that Waltz would have been very interested in, were stories about renegade Apache attacks in the outlaying areas (All attributed to Geronimo... who made his final surrender in 1886) and the stories about the Reavis - Peralta Land Grant Fraud.
Even if Waltz had filed a claim on his mine, he would have still had to cut a deal with Reavis, just like the railroad and large mining companies did to feel comfortable that it would not be taken away from him.
Also... In Waltz's mind at the time, would have been the idea that if Reavis was truly involved with the Peralta's, he may have had specific information about that mine, and just waiting for his claim to be validated before beginning to work it. If Reavis didn't already know about the mine, and Waltz filed a claim on it. Reavis would surely know about it then, and could refuse to give him clear title to it, and claim ownership of it under the Peralta Land Grant.
All Waltz could do is keep it as quiet as possible, and hope that Reavis didn't already know about it. I have also thought a lot about the idea that it was headlines about Reavis' claim, that inspired Peralta to want to make one last trip to the mine (When he took Waltz and Weiser with him) before Reavis became Lord and Master of the whole area???
This would also explain why Waltz and Weiser were in such a hurry to get as much gold out of the mine as quickly as possible, and get it cached somewhere away from the mine itself.
The Reavis case was not finally settled until about 5 years (1896) after Waltz's death in 1891, leaving Waltz between a rock and a hard place right up until the day he died. Maybe this is why he told Julia and Rhiney that they could not do anything with the mine itself (without explaining exactly why) and Ely just made the assumption, that it was because they were not miners?
You can get some background on the Reavis time line right in the DUSA forums at:
http://www.desertusa.com/mb3/viewtopic.php?f=10&t=1979
Best,
Jim