"I'm officially committed to Duke," he wrote on his Twitter account.
On the field, Koppenhaver admits he's not a complete prospect, but the potential is there and there's enough early career production to signal a continued rise in productivity.
"I want to improve on my blocking and my running after the catch ability. I feel like my route running and hands are the best part of my game. My route running allows me to separate from defenders faster, which will help at the next level. At Hart I've learned so much in the passing game and I feel like I am ahead of other players in my routes and knowledge of the game thanks to the coaching I've received."
In Week 2 for Hart, Koppenhaver had a big game against Santiago Corona High, posting eight receptions for 104 yards. Seven of the eight receptions resulted in first downs.
Koppenhaver is rated as a three star prospect and the No. 54 tight end in the country according to Scout.com.