This is a State Park, and it is well maintained. There are restrooms on site, which is very helpful since you are about 10 miles out of Fredericksburg in a fairly isolated area. There are two main viewing areas. The upper deck is free to the public; however, to get the BEST viewing experience pay the $5 fee to enter the lower viewing area. Get there early, and you can walk down to the area near the old railroad tunnel, which will be closed later. The bats come out about dusk, and depending on the time of year (spring to fall), the experience can last from 15 minutes to an hour. The bat colony grows at the summer progresses into fall, which explains the length of time for the bat emergence. The volunteer or Park Ranger will give an informative talk before the emergence, and they share the simple rules for enjoying the experience. The main rules are stay seated and be fairly quiet with no flash photography allowed. We enjoyed it so much that we decided to visit the site two nights.