FIshing Cone Geyser and Yellowstone Lake at Sunset West Thumb Geyser Basin, Yellowstone National Park, Wyoming
The sun was setting behind me and made the sky very yellow. This doesn't capture the sky color completely but the reflection in the pool in the foreground is pretty close.
Yellowstone Lake is the second largest fresh water lake in the world that is above 7,000 ft. It encompasses 136 square miles, with 20 mile stretches of open water.
http://en.wikipedia.org/wiki/Fishing_Cone - February 06, 2011 - 1/80 sec at f / 13 - 24 mm - ISO 200 - 44°25'1" N 110°34'13" W