Photography alert! Many photography fans favor Riverside Geyser for its location on the Firehole River. When an eruption shoots from Riverside’s cone, water arcs over the river. With optimal lighting, the mist produces a colorful rainbow.
Riverside’s activity happens in three stages. For one to two hours before an eruption, water overflows the cone to run into the river. When water pressure ramps up, the cone funnels the stream into a 75-foot-high arch. This stage lasts for 20 minutes or more, allowing plenty of time for photographs. Once the water stops, then the cone spews steam. Photographers can shoot the action from the viewing area across the river.
In the Upper Geyser Basin, Riverside Geyser sits the furthest north from Old Faithful Visitor Education Center. Stop here first to acquire the predicted time of the next eruption. They are usually 5-7 hours apart. You can also use the Yellowstone Geyser phone app to get the prediction. Be sure to account for a minimum of 30 minutes walking time to get via the paved pathway to the viewing area across river from the geyser.