Leave it there and make it a part of the yard. Cut it low around it so it shows nice. Leave it tall and ragged around it. Plant some fall flowers there and leave them there to become a part of it. Plant a bush there. Make it bigger or just taller with more rock. Put a hydrant there. Without water if you wish. Put a pump there. Here in town and all over the Tallgrass Prarie rock comes out of the ground everywhere but where you want it. Tree roots are the same way. Sometimes they get big around the tree and sometimes well away from the tree. It is a bit of a puzzle sometimes as to how to use it or lose it in a yard.