Worlds First Mountain Climbing Cog Railway opened in 1869. (Trivia: It's called a "railway", not "railroad" since the track is less than 14 miles). Mount Washington Cog Railway ride in the White Mountains of New Hampshire. The railway is 3-1/2 mile long, 3 miles of it on trestle. The average grade is one foot in four, or 25%; the steepest grade is 37.41% on Jacob's Ladder. This unigue railway has specially built steam locomotive with their horizontal boilers lower in front so as to make them level while on the mountain. Bio-Diesel locomotive engines have all but replaced just one of the Steam Locomotives in service today. The cog rail is bolted to the cross ties of the road, and into it play with perfect security the heavy toothed wheels under the locomotive engines. Located in The Heart of the White Mt. National Forest.