I just highlighted "index of corporations" from your post, right-clicked, searched, and Google recommended the Arizona Corporation Commission.
I know one of the people on that!
I went back to Navajo County's property tax site and got the company name. I put that into the corporation commission site and it said "The record you have selected is from the Arizona Secretary of State's Database. For detailed information on please click the link listed below."
It had information for other companies. It shows my LLC and the one that my dad had. Bizarrely, allegedly the lady hired to set up LLCs set up mine as in my brother's name.
I never mentioned him to her. So, she just got my name wrong and happened to get my brother's name?
Well, the corporation commission shows my name and the secretary of state's site shows the same information that I found elsewhere for the investment company, although it also says that its business partner is a management company at the same address. It does not give a number for them, either, and neither of those business names show up when I search for that address, but maybe if I search for the management company's name I will get a phone number.
Meanwhile, I already found a phone number.