Roubaix Lake SD ATV Trails?

Staying at Roubaix Lake in south dakota in a few weeks. Any feedback on atv trails near the lake. Looks like you can ride out to custer peak. Can you ride out to the trails on the south side of the like down to riley hill, or do you have to trailer?

Also are there other trails up by custer peak? Mystic hills CG says you can ride out of their CG, but i don't see any trails that show that on the MVUM map.