When I'm looking to locate a roost in Colorado I look for S. or E. facing slopesnear water if there is any and there are places with no water close that you will find turkeys in. Turkeys can get water from the morning dew on grass.
I use a locater call tolocate a roost and they don't always respond to one locater so you may have to use another type. I usually use an owl call but if I believe they are there and they don't respond I will use a coyote call etc. When I have a roost located, I get in early before light to pinpoint the roost but not close enough to bump them.