Much of the publicity material issued by Universal Studios over the years has been more on the side of entertainment than hard facts. Today’s Universal City was not the first Universal City.
The Studio had three openings, so 1915 was the Official Public opening of the studio.
The story of the Universal Backlot based on historical facts will not match the press releases and documents featured in this site.
The studio tour materials are partly for entertainment purposes, and may contain information that conflicts with historical facts based on studio archived pictures and documents.
Because of the large amount of remodelling work done on the Universal City topography over the years, filling in valleys and levelling inconveniently placed hilltops, only a small amount of the backlot is as it was before 1950. However, references to this work are rarely found in publicity materials or advertising brochures. Similarly, there are few references to the fires, floods and storms that have been endured by the backlot sets over the years. Even commercially available topography data (e.g. from Google Maps) is not fully accurate.
There’s also the problem that some studio documents have been misplaced over the years. When they turn up, in the hands of collectors or on Ebay, they’re a goldmine for film researchers. Many such documents can be found on this website.