UPDATE, 1 p.m. Friday: The two mushers who shared Gunnar Johnson’s tent in Nikolai had not been identified as of noon Friday, race officials said. Additionally, COVID-19 testing is being added to two more checkpoints on the return route -- Rainy Pass and Skwentna. In-bound mushers will also be tested in McGrath. Original story: Iditarod Trail Sled Dog Race officials are trying to identify two mushers who shared a tent at a checkpoint with Gunnar Johnson, the Minnesota musher who was pulled from the race this week after testing positive for COVID-19. Johnson, 52, tested positive Wednesday in McGrath, a town 300 miles into the race where every musher is being tested on their northbound journey. He shared a tent in Nikolai with two mushers the previous night.