It was the sixth edition of the nationals, and for the second year in a row individual runners were allowed to compete alongside team qualifiers.
The boys' race was won by Craig Lutz, a junior from Marcus High School in Flower Mound, Texas, in a championship record time of 15:09.2 for the 5 km course.
Lutz came from third to first in the closing stages of the race, overtaking Joe Rosa and just holding off a strong kick from Elias Gedyon.
Boerne Champion held a narrow lead from 3 km on out, gaining the biggest advantage from their second runner Nathan Christianson who finished 16th in team scoring to Ferris' second runner Alexander Avilia who finished 36th.
The girls' race was won by Katie Flood, a senior from Dowling Catholic High School in Des Moines, Iowa, who just held off Kathleen Stevens of Blacksburg High School in Blacksburg, Virginia.