There are several mysteries I still cannot answer with regard to the history of the Disneyland Hotel. Most involve exact dates of when buildings opened or were torn down, or when shops changed names or signs were put up. I am happy to say I have solved one mystery. I saw the picture below and always wondered how they could list "first registered guests" when it was obvious to me that the shops were open at the Hotel with the buildings up and signs in place in the background. Those buildings were not built and signs installed until mid 1956 and the Hotel's first night for guests was October 5, 1955 even though only seven rooms were actually opened that first night.
Here is how I was able to solve this mystery. I found several pictures from the Hotel's first anniversary which were taken in August of 1957. The "official" grand opening of the Disneyland Hotel was in August of 1956 where a star-studded gala was held with over 400 invited special guests. The photo above was actually taken in August of 1957 where Mr. & Mrs. Arnone were brought back to help celebrate the first anniversary but they were indeed the first registered guest on October 5th, 1955....mystery solved!
The photo above features Mr. & Mrs. Arnone at the 1st anniversary with Jack & Bonita Wrather.