The Virginia Department of Game and Inland Fisheries has a very effective electric fence design that you can download: http://www.lwwf.org/index.php/resource-guides Click on ‘Electric Fencing Guide’
March is a time of great risk for apiaries in wooded areas, as the bears are coming out of hibernation and there is no natural food besides grass and skunk cabbages. Suet bird feeders, trash and honey bee hives are a great temptation as they try to feed back up after months in the den. The best thing to do is prevent the damage.
Here’s a great design from Randy Oliver http://scientificbeekeeping.com/scibeeimages/Bear-Fence-PDF.pdf