Last Friday on my way to work I saw four large hawks soaring or perched over the course of my drive.
This morning we saw a really large hawk sitting at the top of a 60 foot pine tree. Ten crows were mobing it. Eventually they retreated and the hawk looked around for a few minutes before gracefully flying away. (I think it was looking at us, and a dog that was walking near by.)
I have been unable to find a really good internet site describing the migration. But from what I have read, they migrate in September and October from their North American nesting grounds to winter in Central and South America.