Just Call Dish
If you call Dish, they will tell you what grade signal you receive based on your address. They just look it up in a database. Unfortunately, this data does take take topography into consideration. I live 18 miles east of the transmitter location, but have a tall hill in the way. (HD is broadcast on a UHF frequency which is a line-of-site type transmission.) Dish tells me I have a Grade A signal when in reality I can't pick up anything.
I tried to work with Dish to get a waiver from the Seattle CBS affiliate (KIRO), but had no luck. KIRO would only accept waiver requests from "the satellite service provider" - not an individual, and Dish refused to send a HD-specific request to KIRO. (They only send non-HD-specific requests. Go figure.)
I also tried to work with Dish to get a signal strength reading to prove I didn't have Grade A or B quality. That way I would not need a waiver. Dish refused to cooperate on this.
Bottom line is that I said "good bye" to Dish after 7 years and am now a Comcast high def customer. (My Comcast service has its own set of problems, but at least I get all of the networks in high def.)
Good luck.