I have 2 areas of my yard with rock. One is/was a dog run, and the other a drain system along by back fence. The dog run is river rock/gravel and was put over plastic sheeting which is now filled with weeds. The drain is full of dirt. What is the best way to seperate the rock from the dirt so I can re-use it. Is there some type of screen/sifter I can rent?

Thanks