I went with a team to explore this site for an upcoming retreat. It was breathtaking. Our tour guide Tracey who is a volunteer was vibrant, knowledgeable and professional all in one.
The Lake literally is a mirror and fishing is allowed.
We looked at rooms in Miller and Bergers houses. Miller House has bunk beds that sleep 4 and a double bed and a bathroom - so 5 persons/room can be housed in this cluster. Bergers cluster has 2 bunk beds and a double bed and bathroom. In addition there are 6 studio apartments on the camp site as well as RVs, and you can also park your personal RV on the camp grounds at a cost of course. A gift shop is there too. A huge gym, large dining area and a mobile food truck. There are some cabins sans bathrooms.
I would definitely recommend Mirror Lake for individuals or groups for a time of reflection, tranquility, tuning in to nature, bonding, etc.