So it appears that the Hawks have selected their nest. We've been watching them bringing in nesting material to build with. Again they continue to call back and forth. Today though, the female (again I presume this) is sitting on the nest waiting for the male to drop off branches. Once he drops them off, he leaves and she continues to form the sides and bottom of the nest. She'll fly off periodically, but generally stays near the nest and waits. Here are today's shots.
Here they are, one on the nest and the other taking off to find more branches:
Here's the male flying off to find more branches: