Fountain Flat Drive, Lower River Group - east side of Firehole River
The River Group is one of the thermal areas you can easily reach from the parking lot at Fountain Flat Drive. Just follow the hiking trail farther south until it crosses Firehole River on a steel bridge. On the righthand (west) side Ojo Caliente hot spring comes into view, on the lefthand side two small paths branch into the River Group. The one in front of the steel bridge follows the east bank of the river, the one after the bridge the west bank. Both give access to different features of the group, since there is no further bridge a long way upstream until Fairy Falls Trailhead at Rabbit Creek. Please note, the River Group is a backcountry setting, lacking safeguarding equipment such as designated trails or warning signs. Given the low number of visitors, the group features comparatively many hot spring accidents and fatalities. So you should only enter the area if you are experienced with safety rules and regulations for backcountry thermal areas. This is also seasonally closed bear management area.
(Update: Since end of June 2017 the entire River Group is closed to public access because of yet another hot spring accident. In the falling night of June 13th, 2017, a 21-year-old Xanterra Parks and Resorts employee from North Carolina strolled around the River Group with seven other people when he fell waist-deep into a by now unidentified hot spring. Fortunately, he survived, but suffered 3rd degree burns on the lower 40 % of his body.)
Although Ojo Caliente is located across Fountain Flat Drive at some distance to the other members, it is regarded as part of River Group. This spring shows superheated boiling, but otherwise no geyser activity. Featuring temperatures around 93 °C (200 °F), Ojo Caliente is one of the hottest springs in the park. In June 1958 the spring was the scene of a tragic accident, when a 6-year-old boy from Minnesota slipped into the boiling water. For a short moment he was submerged up to his head, what sentenced him to death. Two days later the doctors lost the fight for his life.
From Ojo Caliente firstly we follow the east bank of Firehole River. On the lefthand side, embedded in the slope of a hill, a mud pot called Grotto Spring attracts attention with widely audible gurgling and splashing.
In close distance to Grotto Spring, directly on the bank of Firehole River, Baby Bathtub Spring lives up to its name (only by appearance, not in terms of functionality, of course!).
At Baby Bathtub Spring the river curves to the west. Northeast of the river bend a huge number of unnamed hot pools is scattered about the area, which merges into Pocket Basin. The next photos show the three pools closest to the river, identified by their designations from the RCN database.
Proceeding south at some distance to the river, you come across numerous hot springs until you reach Azure Spring. LRNN109, LRNN110, and LRNN113 belong to the more striking ones.
LRNN110 shows a distinct internal current of hot water, running from a smaller pool into a larger one. Regarding shape and current it comes close to an hourglass.
Azure Spring, not far away to the southeast, is usually an intermittent spring, but weak spouting activity has also been observed on rare occasions. Farther to the east the Pocket Basin Mud Pots adjoin, Yellowstones largest collection of mud pots.
