On the way back from visiting our daughter in Indiana, we stopped for a few days at Nolin Lake State Park. We will definitely return. Here is a map of the park.
Campground
The 32 water and electric campsites are spread out; many back right up to the lake. They have 27 primitive sites you can reserve as well.
Facilities
They have a nice playground, bathrooms, dump station, basketball court, disc golf, a beach for swimming, as well as a boat ramp.
Hiking
We took the 1.9 mile Waterfall Trail section of the trail system. Part of the trail is accessible for bikes IF the area is not too muddy. The day we took the hike, bikes could not use the trail. When you come to the first fork, you can take a left or a right. We took the left section, which is an easy 15 to 20 minute hike to the waterfall. If you do not have much time, you can just go back the way you came. We took a few offshoots of the trail to go to the base of the waterfall as well as to stand above it. We then backtracked to the main trail and continued on the loop. It took us approximately 40-45 minutes to get back to the beginning, so the right fork is twice as long to get to the waterfall. This section also connects to the Omega Loop. They do not have any detailed maps of the trail, so the one in the park map I linked to is as good as you will get. It is not really accurate. However, the trails are pretty well marked, so you should not have any trouble. Overall, you have 7-9 miles of hiking trails in this park.
When we return to Mammoth Cave National Park, we will definitely stay here again. This park if off the beaten track, but well worth it.