Looking at your picture/diagram from a bird's eye view, I have to guess at the distance between your controllers. Somewhere around 120 feet between them? Am I even close?

There are wireless units that will cost you, but will work. Many here (myself included) like to use Ubiquiti because of their ability to work across great distances. For instance, I have several (in our park show) that are easily reaching 750 and 850 feet. There are other wireless that can do about the same.

The fact that you are also crossing your road adds to the fun as well. Of course you can trench or bore. It is up to you.