The Grand Prismatic Hot Spring is located in the Midway Geyser Basin along the Firehole River; indeed, It's overflow along with that of several other hot springs empties directly into the river. The multi-hued concentric circles that emanate out from the blue center of the spring (not very visible here because I was not aware of the trail to the overlook on the ridge behind and to the left of this frame) are caused by varying species of heat loving organisms. Each colored ring signifies a different temperature and the different thermophiles that can live there. To survive in the harsh environments, the organisms produce photosynthetic and chemosynthetic pigments, which in turn reflect specific wavelengths of visible light, making them appear in a rainbow of colors to the human eye. The spring is located just west of the river which in turn parallels the western side of the Grand Loop Road (US Highways 89 & 191). The view is to the southwest from the boardwalk along the eastern edge of the spring.

Submitted to the March, 2018 Secret Photographer Contest (SPC) @ votingmachines.panoramiogames.com/entries-review-form.php?contest=SPC&year=2018&month=3&from=C as entry #37 with the title "Sky Clouds; Steam Clouds; Reflected Clouds".