My sister and are going to be driving from NY to SD in early/mid April and need to be in Kentucky by May. We wanted to visit the Badlands, Mt Rushmore, and Wind Caves. We were hoping to do some light hiking along the trails. From what I've read April does not seem like the most ideal time but wanted to get other opinions. Will there likely be snow in Apr? Will we still see the animals? Basically we want to know if it is us worth visiting SD at this time.