Abandoned House Owner Question

[Chantel Haywood]

Hi! I have a question about a project I'm working on. I have been hitting some road blocks and I just don't know what it means. I entered this properties address into the county assessor page; nothing came up. I then entered it into the Montana Cadastral Map. The listing came up, but it said it has a different address. (Later to find out, the property lot also owns the building behind it.) - What I don't understand is the listed owner reads "23rd Ave Condo Master - General Delivery Bozeman, MT"

I looked up what Condo Master means, and searches related to insurance companies came up. What I don't understand is if an insurance company owns it, why would it have general delivery mail? Does anyone know more information about  Condo Masters? I called the county assessor and she didn't know what it meant. Thanks in advance!!