This is quite an intriguing legend, some folks are highly skeptical of it on various grounds. Perhaps we can lay some of those doubts to rest.
Firstly, the presence of gold in the Canon del Oro is not only well established but easily proven. There is every reason to believe that a lode gold mine could exist in the mountains, that perhaps was the source of some of that placer. Or perhaps it is not related to that placer deposit at all?
Next, an iron door is far from impossible.
This one is perhaps the very one referred to in the 1930s CA story
Can you see it? Here is a closer shot - this is in Joshua Tree national monument by the way
While an iron door certainly would have been trouble and expense, it is far from impossible and actually would be a logical way to try to seal up a particularly rich mine to keep people out. The padres were not stone age men, they were highly educated for their time and certainly could have obtained the iron for the door. In fact an iron BOUND door would be much more likely and easier to have built by a blacksmith or the padres themselves if they had blacksmithing abilities.
In sum, this is far from the most unlikely of lost mine tales, it is rather more than just possible. Considering the placer of Canada del Oro, it is quite likely that a lode gold mine might be hidden in the recesses of the mountain, in a relatively inaccessible place, to be happened upon by hikers and hunters occasionally over the centuries. It is more likely than having a number of different people making up virtually identical tales of accidently finding a well hidden mine sealed by an iron door, and then being unable to find it again.
This reminds me of a little 'project' I had intended to do here, for folks who doubt how a mine could be lost at all. I don't have the time to do it tonight but will try to do it soon, something to illustrate how a mine can be so well hidden by nature alone, that you can literally pass within ten feet of it and not be able to see it.
Please do continue;
