Caption: A mid-year afternoon weekend view of GO Transit's Willowbrook Yard looking south-west, from a slide processed June 1978. Vantage point is in the vicinity of Islington Avenue bridge.
The municipal water tower is a long-term landmark, while the 4 tall chimneys of Lakeview Generating Station on the south-east Mississauga lakefront stood from circa 1960 until demolished in June 2006.
The Mimico Yard coaling tower is still standing to the right of the 4 chimneys, straight above the back doors of 2nd-from-right single-level coach (near track). The west observation/control tower of Mimico Yard is to right of the water tower, above the bend in the near track.
At this time CN retained all south side yard tracks, left of the tied up GO trains and Oakville sub main lines. VIA did not relocate to the south side (Toronto Maintenance Centre) until the closure of Spadina circa 1986 - when Spadina roundhouse was demolished to make way for the Skydome stadium.

Nearest single-level GO coach is GOT 1019. The GP40TC locomotives coupled to the train of single level coaches are GOT 503 and GOT 504. Part of two GO GP40-2W's are at left, one partial cab number looks like 709. Almost new F40PH's tied up in the yard included GOT 510, 511, and 512. Note that GO locos are at the west end of their trains in 1978; they got moved to the east end of GO trains long ago.

GO Transit's modest maintenance and fueling facilities were on the opposite (east) side of Islington at this time, the Mimico yard east tower also still stood. Note the absence of GO Transit's main diesel shop which was built in the near right in the 1980's, west of Islington Ave bridge.