We love the swimming hole even when it is Cold out. The water is always warmerThen you would think due to the thermal runoff

one of the rivers that make Yellowstone NP lush and green...come very cool spots/pullouts along the way to take in the view and take photographs...if one is lucky one might see some elk or a bear or two...while we were there there was a solitary bull bison wandering about the roadway...early in the AM or later in the afternoon are my favorite times to visit the area

Firehole River runs throughout the area south of the west entrance road. I saw it a few times while I was at Yellowstone, but I think the coolest thing I saw with it was some of the geysers feeding into it, creating waterfalls and more steam, as the hot water ran into the cold river. I got some neat photos of it, too. It is also a popular fishing area.

We went on an evening tour where this was the highlight. There is a small loop road leading in to a remarkable canyon and waterfall.

The Firehole river is a bit warmer due to the many hot springs that feed into it. You can see it quite well in the Midway Geyser basin near the Grand Prismatic Spring and also the Upper Geyser basin near Old Faithful.