If your goal is to increase the elevation of the yard near the fence you could do a retaining wall but I think you would get tired of chasing balls into the ravine.
Depending on the details of the fence construction you could use it as a gabion wall. If it is well built you could pile rubble and crusher against it and then fill with well draining gravel. Landscape fabric 4" below your final grade to keep your topsoil from filtering into your drainage gravel, then topsoil for grass.
IMO that treatment is sinfully ugly from the outside but it is functional and if no one has to look at it....