Thunder on Tennessee Pass The summer monsoons in Colorado’s high country have arrived again on the afternoon of August 2, 1996, as an eastbound Southern Pacific freight that has been climbing the steep grade out of Minturn is now slowing to a stop on the main line at Tennessee Pass. From around the curves, a westbound SP taconite train takes the siding and sends smoke into the rarified air as it notches up for the last mile of grade to the 10,221 summit of the pass. Thunder and rain continue in the background over Colorado’s highest peak, 14,433-foot Mt. Elbert. The sunlight is receding and I soon move on, deciding to photograph the taconite train exiting the west portal of Tennessee Pass Tunnel since the freight frogged me at this location.