I spent a couple days climbing around the slopes and forests of Mullan Pass with David Honan. After Dave had departed for other adventures, I returned to one of my favorite spots. The sound of BNSF5331 could be heard for about 40 minutes before arriving under my perch high above Skyline Trestle. For those who have never visited Mullan the sound of a unit train climbing the 2.2% grade with low-bass reverberating off the mountainsides is not one that is soon forgotten. It draws me back year after year....