You can plug in where you are at using a site like http://www.tvfool.com/ and it will tell you which way the stations are and the likely hood you can actually pick them up.
In the hills, like where I live, I can tell you from experience (messing around at my house) that getting signals can be voodoo.
Even trying a couple high end home antennas, I found they gave totally different results and moving them a couple inches would make the difference of what channels I would get. This is even though all the channels I want all beam off the same mountain.
Moral of the story is that odd things happen to the signals when they bend over hilly terrain (flat is not so much a problem). Don't believe the hype of some of the marketing of these antennas that promise to get you every channel.