Every year in late May or early June, hundreds of visitors near Elkmont Campground see the naturally occurring phenomenon of Photinus carolinus, a firefly species that flashes synchronously. Since 2006, the National Park Service has limited access to the Elkmont area for the eight days of predicted peak firefly activity. This helps reduce traffic congestion, provides a safe viewing experience for visitors, and minimizes disturbances to these unique fireflies during their two-week mating period.

A total of 1,120 vehicle reservations, 140 per night, will be issued through the lottery process. The results of the lottery will be available no later than Monday, May 6. Each reservation allows one vehicle with a maximum of seven occupants to park at the Elkmont viewing location. The number of daily reservations is based on parking capacity and the ability to safely accommodate a large number of viewers on site will minimizing resource impacts.

Lottery applicants may enter two dates to take part in the viewing opportunity over the eight-day period. The lottery system uses a randomized computer drawing to select applications. All lottery applicants will be charged a $1 application fee. Successful applicants will automatically be given reservations and a $24 reservation fee will be charged to the same credit or debit card used for the application fee. The $24 fee covers the cost of awarding the reservation, as well as on-site portable restrooms, supplies and nightly personnel costs for managing the viewing opportunity.

Reservations are non-refundable, non-transferable and good only for the date issued. There is a limit of one lottery application per household per season. Regardless of the outcome, all lottery applicants will be notified by e-mail by May 6 if their application was successfully drawn or not.