This image is a geological feature called "The Subway" and is located in North Creek in Zion National Park. In addition to being a rather chilly place, the Subway, as its name suggests, is also quite dark. This image was exposed for around 20 seconds. Luckily the light is rather balanced with the warm orange light at the end being not too different in brightness than that of the blue shadowed areas. The yellow glow is actually light that is reflected into the Subway from sunlit, brownish sandstone just to the right of the frame. One of the most striking features of the Subway is the green pools, one of which can be seen on the right side of the image. It is a complete mystery to me. I can't explain the color or its illusionary appearance, but it certainly makes a nice element in a photograph.