Arizona refiners have always held a special place among serious collectors of silver ingots. One, that has really gained traction in past years is Gila bars. I’ve been privileged to own several and still own one today. Based on discussions among the serious collector community, it is thought that the company operated out of Tempe, AZ. I’ve seen many dates discussed regarding their years of operation (as early as 1916), but there was a Gila Development Corporation established in AZ in 1960 and dissolved in 1985. This could be the one, but not definitive.
These bars only came in 5 and 10 oz class from what I have seen. Both 10 oz and 5 oz are extremely rare and hard to find.
Vintage Silver Bars 