Austin Yunker took ninth in 18 : 11.2 , Tyler Frisbie finished 15th ( 18 : 36.7 ) .
Alex Heckman was 17th ( 18 : 42.2 ) .
Austin Yunker took ninth in 18 : 11.2 , Tyler Frisbie finished 15th ( 18 : 36.7 ) and Alex Heckman was 17th ( 18 : 42.2 ) .