A long-term relationship between Red Frog Events and Dover Motorsports was announced Sunday - the final day of the 2013 installment of the Firefly Festival.

As the first bands were setting up to play Sunday morning, Dover Motorsports President Mike Tatoian announced a 10-year agreement with Red Frog Events that the Dover International Speedway would be the exclusive home of the Firefly Music Festival.

"Because of the success of last year, and the anticipated success of this year," Tatoian said, "rather than negotiating a contract every year we thought it would be best to negotiate some general terms that both sides are favorable to for the next ten years so we don't have to repeat that same thing over and over again."

The details of the deal are still being discussed but some of the options include a cancellation clause for Red Frog Events each year. But we do know this much: Firefly will return for a third year at The Woodlands June 20-22, 2014.

Red Frog said it was pleased with the grounds and its ability to adjust to continued growth.

"We're really happy delivering the similar experience that we had last year – and even an elevated experience – to twice as many people," said Firefly Festival Director Greg Bostrom.

It is estimated that this year's event brought in more than 65,000 people to the capital city of the first state and Bostrum expects even more music fans to attend next year.

With so many people in town for the three days of the festival, Tatoian added that the benefits of the festival reach far beyond Red Frog and the Speedway as people get to know the town and spend money while they're here.

"There are 50 states and [several] countries represented, and not to say that they wouldn't have been here otherwise, but they probably wouldn't have been coming to Dover, Del. otherwise," said Tatoian.

Festival goers are already planning for a return to The Woodlands next year.

"I came last year and had so much fun that I bought my tickets for this year as soon as they went on sale," said Kiley Douglas. "I've had fun this year, too, so if I can come back next year, I will."

Sunday's fun almost seemed to be in jeopardy, though, when partly cloudy skies began dumping rain around 1 p.m. As the bottom fell out, fans found themselves drenched but still happy to be listening to their favorite bands.

Bart Monelithy drove to Dover from Ohio just to see several of his favorite bands, and with the faithfulness of a postal employee, he said that nothing short of a major disaster could have kept him away.

"After the money we spent to get here, there's no way a little rain or even a lot of rain could keep us away," said Monelithy as he tried to rake the mud off his shoes. "As long as the bands are willing to play, we're here to stay."

And, play they did. Sunday's acts included Ben Harper and Charlie Musselwhite who filled in for the last minute cancellation of The Lumineers, 1990's indie folk band Dispatch, The Last Bison and Delta Rae.

Passion Pit went on at 6:30 p.m. and tried to make up for last year's cancellation only to wind up cutting their set short by about 30 minutes after lead singer Michael Angelakos said that he was having trouble with allergies and just couldn't seem to hit the notes anymore.

Indie darlings Vampire Weekend took the stage at 7:45 p.m. on The Lawn, followed by Foster The People, at 9:30 p.m. on the Main Stage. Their last guitar riffs faded out at 11 p.m., bringing the 2013 festival to a close.