Is there a way to use radio to restrict communication to optical line of site at distances greater than 10 miles?

For example, the signal is transmitted directionally from a mountain top fire lookout, only to be received if the transmitter was also able to hit the receiver with a laser beam. Well, there could be some tolerance for obstructions but not if the receiver is hidden by a hill.

If possible, what frequency range and equipment would be used? It doesn't matter if it's voice or data based communication... I'm more wondering if/how radio is used like this.