MELLETTE - The Boekelheide name is virtually synonymous with Northwestern cross country. So it’s only fitting that Derek Boekelheide has come full circle, from coach’s son, to budding young talent, to senior leader and, now, assistant coach. Boekelheide, who continued his running career at South Dakota State under head coach and former Olympian Rod DeHaven after wrapping up his time at Northwestern, returned to his Wildcat roots this fall, coming on as an assistant coach alongside his mother, head coach Kris Boekelheide. And it couldn’t come at a better time. “We have the great problem of having too many runners,” Derek said. “It’s a lot for one person to be coaching sixth graders all the way through the defending state champ (who happens to be his younger sister, Ella). … It worked out that I just finished college and came home.” Boekelheide didn’t come back specifically to coach. Instead, he returned to the family farm. Coaching just sort of fell in