It was the first show to sell out prior to the fair since Poison performed five years ago and thousands of young fans from Perryopolis to Pottsville packed into the Grandstand and track to see the popular music and television stars perform.
The group consisting of Kendall, Carlos, James and Logan (no last names given) also have a popular show on Nickelodeon.
And many fans who could not get tickets, pressed against the gates hoping to catch a glimpse of the show through holes in the fences.
The band opened its show with "Famous" and followed with such hits as "Boyfriend," "Big Time Rush," "Worldwide," and "Stuck." The band also paid tribute to another popular foursome from years ago when it performed "I Want to Hold Your Hand," by the Beatles.
Through much of the show the band sang and performed choreographed dance routines but also did an acoustic set where they all sat on stools and sang to an acoustic guitar.
For much of the show, the predominantly youthful crowd in the track seating area stood on their chairs and danced, screamed and sang along with the music.
Many fans like Jessica Russell, 15, Megan Campbell, 15, and Jessica Kulwicki all from Perryopolis drove for hours to attend the show and were wearing homemade T-shirts and carrying signs paying homage to the band.
The three friends said they drove for four hours to come to their first Big Time Rush show.
"It was amazing," said Russell.
"I thought it was really good," Campbell said. "I liked it all."
Kulwicki said she too really liked the show but said she was "very disappointed" she didn't get to touch any of the band members like her two friends did when they came down from the stage.
"It was awesome," Madison Irwin, 12, of Schuylkill Haven said.
Many of the locals too said they enjoyed the show.
"It was the best experience I ever had," Sarah Wriglesworth, 16, of Curwensville said.
"It was good," said Nick Coudriet, 7, of Philipsburg.
Coudriet said he was a big fan of the band and their TV show and said they have all their episodes recorded.
The band performed for about an hour and a half and fans stayed for more than an hour afterwards hoping to meet or get autographs from band members.
Those in front of the stage scrambled to catch water bottles and guitar picks used by the band during the show that were being thrown off by stage hands as they tore down the set and packed away the instruments.
Clearfield Mayor James Shell who is also a fair official said Friday before the show band members wanted to go to the fair so they took them around the fair on golf carts. While out, he said band members bought two mini-bikes and two four wheelers from a local vendor at the fair.
"They dropped a lot of money in the local economy," Schell said.
And Schell said the band members told him they were going to try to use their new toys on their T.V. show.
"I told them to mention Clearfield," Schell said.