LOS is everything with OTA antennas. Anything between you and the transmitter tower will attenuate the signal. I'm shooting directly through a 40 foot pine tree and still picking up my locals from about 45 miles. Trying to get stations at 100 miles you need height, good LOS from your antenna to their antenna, and a good antenna. I know a guy that picks up stations at about 90 to 100 miles regularly, but he has a 60 foot telescoping tower and a BIG antenna.