When Brenyn Otto’s brother-in-law, Tanner Robberstad, encouraged him to take on the Wilderman Offroad Triathlon, Otto found it difficult to turn down the challenge. Robberstad had completed Wilderman nine years earlier and decided to return for this year’s race through the rugged Pembina Gorge. “When he signed up for this year, he was encouraging me to sign up every time the subject came up,” Otto…