1 of 6 Logan High School environmental science and biology teacher Hans Doderer, center, and two students release a bag full of trout at Buffalo Creek on Wednesday, May 5. DYLAN VIDOVICH | Logan Banner Logan High School environmental science and biology teacher Hans Doderer instructs students during a field trip to Buffalo Creek on Wednesday, May 5. DYLAN VIDOVICH | Logan Banner Logan High School environmental science and biology teacher Hans Doderer demonstrates how to use a pH testing device during a field trip to Buffalo Creek on Wednesday, May 5. DYLAN VIDOVICH | Logan Banner Logan High School environmental science and biology teacher Hans Doderer demonstrates how to use a pH testing device during a field trip to Buffalo Creek on Wednesday, May 5.