As most people know, the southern wing of the old MacArthur Elementary School was built in 1915 as Denfeld High School. (The modern Denfeld opened in 1926 and the old Denfeld became West Junior; MacArthur was built in 1957; West closed and became part of MacArthur in 1983; MacArthur was replaced with a new building this past fall). The photo above is of the 56th Avenue West entrance to the old MacArthur, which has always been considered the back door.
The section of the building that protrudes out and comprises the rear entrance is not original. It was built in 1994 to provide an elevator for improved handicap accessibility. There was a stone block over the entryway, covered by this addition, that read “Robert E. Denfeld High School.”
If anyone has old photos of the entryway, please post them. The old MacArthur is in the process of being gutted and prepared for demolition, so if that entryway exists under the current one and anyone would like it to be saved and either left on the current site as a monument to the old Denfeld or moved to the current Denfeld campus, the time to act is drawing short.
Update: All evidence points to the conclusion that the old Denfeld block was removed in 1994. Details in the comments.