I recommend a one antenna solution , a Winegard HD7000R antenna aimed at about 350 degree magnetic compass. Here is how to aim antennas ,
http://www.kyes.com/pointing/pointing.html. Mount the antenna above the roof with one of these antenna mounts.
http://www.ronard.com/909911.html ,
http://www.ronard.com/34424560.html ,
http://www.ronard.com/ychim.html. . The long rods at back of the antenna will help block multipath , ( reflected signals ) that are a real problem at your location between the mountains. Reflected signal interfer with a tv tuners ability to tune in channels. Here are some places to buy antennas and etc. ,
http://winegarddirect.com ,
http://www.solidsignal.com ,
http://www.amazon.com