Hillsdale, but when?

One more photo from John Wardin's family album. It shows the "Hillsdale Triangle" in the upper portion and the Fulton Park Dairy beneath and to the south of SW Capitol Highway running diagonally across the photo. Note the large milking barn at the corner of Bertha and Vermont (which was Hoffman Road). John and I are puzzled about the year. We reckon it must be the early Fifties. There are clues to be found and checked out. For instance, Robert Gray School appears at the top. When was it built? When were the houses built along Sunset Boulevard? The original library hadn't been built — the dog that didn't bark!

Perhaps others will have ideas.