A winter storm buries the Sierra Nevada. Embedded in the blizzard: the main line of America's railroad. For two days the major west-east route across America is shut down by snow, tying up billions of dollars of goods, trapping an entire train crew in an avalanche. A vision from the past is sent to rescue modern day transportation. The Rotary Snow Plow, invented in the 1800s, roars to life and heads up some of the steepest mountain terrain in the world. Its mission: save the crew and re-open the rail line over Donner Pass. Men and machines vie with the mountains and elements, a true story of survival.