This area is a short, spectacular section of the Left Fork of North Creek. The canyon system is called the Great West Canyon, including both the Left and Right Forks. The Subway section is not marked on maps, but is where the Left Fork tightens up and twists sharply, between North Guardian Angel and Guardian Angel Pass.
Be very cautious when hiking to the subway. It is not the way to the subway that matter, it is the way back. If one did not mark or carefully remember the exist trail, one could be lost and spend the night in the wild. The temperature at night could drop very...very low. At 6:30PM, this place is jet-black. The only thing you see is what your flash-light allow you to see.