Reddit reviews Menace at Mammoth Cave: A Kit Mystery (American Girl Beforever 1934: Kit Mystery)

The week after Labor Day would be better if you want solitude but the backcountry campsites probably won't be crowded either week.

Do not underestimate the impact of humidity on your body. Early September still feels like Summer, with temperatures frequently in the mid 80's and daytime humidity levels of 70% to 90% for a heat index that is consistently in the 90's. Sometimes the weather pattern is nearly tropical, with brief afternoon rain showers where it seems like the sky is dripping water rather than actually raining.

The only thing about the terrain to note is that the Green River is flanked by bluffs. If you choose trails that take you down to the river and back up to the top you will be covering a lot more hill climbs than you might expect.

Don't skip the cave unless you are uncomfortable underground. It's 400+ miles of awesomeness. The big group tours are touristy but a good option if you don't want to spend much time. The Intro to Caving tour (a whole afternoon, all gear provided by NPS) is pretty amazing.

My favorite sensory memory at Mammoth Cave is sitting at the bench outside the Historic Entrance, feeling the cool air rush out of the cave opening like an air conditioner on full blast.

I like to read about the parks before I visit. One of my favorite books about Mammoth Cave was one I read with my kid. Believe it or not, the American Girls books (tie-in products for the series of historical dolls) are often really good about capturing multiple sides of history with nuance. I recommend Menace at Mammoth Cave: A Kit Mystery, even for adults. It focuses on the time that the park was being built by CCC workers and the community of residents that was displaced by the creation of the park, with plenty of natural and historical info worked into the plot.

Enjoy your trip!