Great hiking, nice mix of forest and prairie.
It's Oct now & the maples have turned so the primary color is yellow with dashes of orange & green. This being SD, the wind has blown down a lot of leaves, now. Paths with most maples are down in the Hollow, so get here before 5, or even 4pm for best sunlight. If you are sure-footed & can hike a hill, take the horse path across the road from the vault toilet and climb up for a scenic overlook of the whole Hollow, or take the 1st left & enjoy a crunchy still-leafy trail that winds across that S slope & to the road. Horsepath trails with the most still-leafy trees are towards the W end of the park & on the S slopes of the N hills. But make no mistake, most of these paths have sections of challenging hill-age. White spur trail/gravel road is mostly leafless at this point. Road thru the park is also beautiful & winding & about 2mi long, with an option to turnaround at the horse camp picnic area or you can continue onto the gravel into a scenic lake area.