The senior helped the Red Devils relay teams win two state title at the Class 1 state meet in Jefferson, City, Mo.
Yahn was a member of the victorious 800 and 400 relay teams to cap his high school career.
"He's all-state 14 times, and 10 of them are on relays," Chaffee boys coach Tyson Moyers said. "He was all-state in two as a freshman and four for sophomore, junior and senior year."
Yahn added a fourth-place finish in the 800, and he helped the 1,600 relay team finish fifth last weekend. He graduates as the most decorated track athlete in Chaffee's history.
"There's no greater feeling right now than what I did," he said. "It feels amazing. Hopefully no one does it for a long time because it feels pretty good."
Chaffee ran the fastest time in Friday's 800 relay preliminary round. Travis Hall, Tyson Estes and Zac Dannenmueller joined Yahn on the relay team.
"We ran 1:33.31, which broke our school record, [Friday]," Moyers said. "We ran 1:33.04 in the finals. We won it going away. We were the only team that ran faster [in the finals] than [the preliminaries].
"We talked all year that it's our race. We talked that if you're going to win the 4x200 at state, you've got to go through us. It's something we've really talked to those guys about. They keep up with times around the state. We've been real fortunate. We've had a great run."