Right around sunset today there were several thousand crows gathering to the south and to the east of Bloomington's College Mall. At one point the sight of hundreds of crows in flight reminded me of the plague of flying monkeys filling the sky in the Wizard of Oz. :-)
These birds don't appear to have one specific roost. They seem to rotate around the east (and northeast) side of town. Sometimes in the evening I hear them just a little bit to the west of where I live. Tonight I first heard them calling loudly from the NNE. But when I finally saw them, they were to the SSE of my house.
I wonder how crows pick their gathering places?