The Firehole River in Yellowstone National Park must be one of the most aptly named bodies of water. It enters the Upper Geyser basin just behind Old Faithful through a heavy forest.
It loses tree cover as it enters the Upper Geyser basin.
Super heated water from thermal features enter the river. The constant temperature is a home to a multitude of colorful thermophile (heat loving) bacteria. The River runs near iconic Old Faithful Lodge.
Bison graze for meager food along the warm banks of the river. The river is only 21 miles long as it flows from the Continental Divide, into the Madison River which is one of the three main tributaries of the Missouri which joins the Mississippi as the longest river system in the contintent.