Mangum is a 6-foot-3-inch, 190-pound quarterback prospect from Eagle High School just north of Boise, Idaho. His older brother Parker was a sort of jack-of-all-trades while at BYU, playing most positions on offense during his four-year stint.
From his brother, Tanner learned a lot about BYU's program and started coming to camps at BYU when he was in the eighth grade. Since that time, he kept in good contact with coaches, which culminated with an official offer this past February.
BYU wasn't his first offer, however, as Boise State was the first school to officially solicit his services when they offered him this past September. September wasn't exactly the best month in BYU football history, much less the month that followed it. Considering that he had yet to receive a BYU offer at that point, it would be easy to assume that he began leaning Boise State's way.
"Not really at all," said Mangum regarding whether he had ever seriously considered Boise State over BYU. "I really like Boise a lot and I have a huge amount of respect for Coach Peterson and the program he runs there, but BYU was always the place I wanted to attend school and play football. Boise would have been a great school to play at for certain, but BYU has always been my first choice."
So why stay with BYU when they were struggling so mightily with no end in sight this past fall?
"BYU is more than just football for me," he responded. "It's everything that BYU is other than a football team that made me keep my desire to go there. The ideals they have in their program, the character of their coaches, the goals they have, that's the reason I kept my desire to go to BYU no matter what."
BYU obviously rebounded and now looks to have a very bright future. With a good, young quarterback such as Jake Heaps at the helm for the near future, as well as all of the team's other significant parts, BYU should be set to reach new heights. All of this hasn't been lost on Mangum.
"BYU is a great place to play quarterback with the great tradition they have there," he said. "It's really the only place I've wanted to play quarterback at. They have a great quarterback coach in Coach Doman and I couldn't be more excited to learn from him."
BYU came through with an official offer in February, but according to Mangum, he had prior strong indications that the offer would be forthcoming in due time. Following his official offer, he made an unofficial trip down to BYU this past weekend.
"I knew in the back of my mind that I was going to commit on the trip," he mentioned. "I had thought about it a lot and I knew I was coming to BYU, so committing was something I planned on doing."
During his trip, he was able to attend meetings with the players and observe practices. He particularly enjoyed seeing Heaps work during practices and in the meetings.
"He's obviously a great quarterback, but it was great seeing him in meetings and the intense desire he has to get even better," he said. "I learned a lot just watching him and how he worked with coaches this past weekend. I want to be like that, always striving to be better."
Mangum is well aware of when Heaps completes his senior season, and knows that he should have ample opportunity to compete for a starting spot immediately following his planned mission service. He'll be leaving for his mission the summer after he graduates in 2012, and then could be good to go in 2014.
"It could be great timing for me to be sure," he said.
During the practice session he attended, he enjoyed seeing BYU's new offensive system and could easily see himself running it effectively.
"I'm a drop-back passer, but I also have good mobility," he explained. "BYU's system is a great one for me with how they run things. There is going to be a lot more play-action and stuff like that, which I like a lot to be sure."
Following the practice session on Friday, Mangum met with both head coach Bronco Mendenhall and Coach Doman to inform them of his decision to commit.
"They were very excited for me," he recalled. "They both just expressed how happy they were to have me as part of their program. It won't be for a while until I'm able to play for them, but I know that the program will be in great shape when I return."
Mangum is confident about the future state of BYU's program because of its core principals. As long as Mendenhall is the coach in place, those principals won't change.
"It's what I love about Coach Mendenhall," he said. "It's not about football or all about football, it's about becoming a better person. I love that about the football program and I know that Coach Mendenhall will always have those principles in place no matter what."
Mangum also loves the school.
"BYU is the best place for me to get a great education and be in a great environment," he mentioned.
Mangum's options weren't limited to just Boise State and BYU. He had already garnered offers from the likes of Utah, Arkansas and Oregon State, with even more offers undoubtedly on their way had he done the summer camp circuit before committing.
"I just knew BYU was the place I needed to be, so that's why I committed this early," he summed up. "It means everything to be a part of such a great program. It's a huge honor to have the opportunity to continue the great tradition of great quarterback play at BYU."