"I don't how to describe how great it feels to finally make this decision," said the nation's 23rd-ranked offensive tackle.
"I knew a while back I knew I should make the decision now," he said. "I mean I am ready. It's where I want to be."
Callahan will get a head start on his college education at Auburn as he plans to graduate early and enroll in January. The 6–6, 280-pound Callahan said the Auburn coaches see him fitting in perfectly as an offensive tackle for the Tigers.
"They were fired up," Callahan said. "I called Coach (Gene) Chizik, Coach (Gus) Malzahn, and they all just said we are fired up and they're excited to have me start."
Callahan, who plays for Chaparral High School in Colorado, said that distance was not a factor and that his parents would likely make the move as well.
"If they weren't here, it would be a place I'd want to be without football," he said. "So it's one of the greatest towns, colleges, campuses and the football team--they're one big family and I'm really excited to be a part of that family."
Callahan said he'd like to attend a game in the fall as his official visit to Auburn, adding that he has no plans to take any other visits. "There's no other school that compares to it so it's the best choice I could ever make," he said. "It feels great. I wouldn't want to spend it anywhere else. It's one of the best towns you could live in."
Callahan said that he will now turn his sights to recruiting for Auburn, especially four-star offensive tackle Patrick Miller, who he'd like to see join him as a Tiger. Miller was a visitor to Auburn's Big Cat event on Saturday.
"We're going to win another national championship," Callahan said. "We're all set on that."
One of the top prospects in Colorado, Shane Callahan from Chaparral High School, was one of a large group of outstanding prospects who visited Auburn for Big Cat Weekend, the third time Auburn has held the event.
"I was pretty much set (on Auburn) before this," said Callahan.
Callahan, who is rated a four-star prospect by Scout.com, visited Auburn earlier this year for a junior day and came away impressed.
Callahan had offers from the University of Colorado, Michigan, Arizona and others. He said after making the trip back to Auburn with his parents it felt right and he is enthusiastically on board with Chizik's defending national champions.
Callahan said he is excited about the opportunity to learn from Auburn offensive line coach Jeff Grimes, who the prospect has known since Grimes was a assistant head coach at Colorado.