Grand Prismatic Overlook Trail – Yellowstone National Park, Wyoming

Grand Prismatic Spring, the largest thermal spring in the United States and the third largest on Earth, radiates both heat and beauty from its chromatic depths—the massive circular spring has a diameter of 350 feet and is nearly 125 feet deep. Its deep center glows an azure blue, changing from green, to yellow, to red and orange as you get closer to the edge—this scattering color pattern makes it one of the most iconic sights of Yellowstone and one of the most beautiful natural phenomena in the world.

Yellowstone National Park offers the visitor two ways to appreciate the beauty of Grand Prismatic Spring—the overlook offers an aerial view from above and the boardwalk permits an up-close look at the pool from ground level.

The best time to view Grand Prismatic Spring is after the sun has warmed up the air—colder air causes steam from the thermal areas to obscure the view, so in this case the early bird does not get the worm, wait for midday heat to burn off the steam for an unobscured look at the hot springs.

The hike to the Grand Prismatic Overlook, one of the park’s newest official trails(opened in 2018), begins at the Fairy Falls Parking Area—the gravel parking lot is relatively small for such popular attractions, so you might have to park alongside the Grand Loop Road and walk(a must if you are traveling in a RV, as buses and oversized vehicles are not allowed in the parking area).

From the Fairy Falls Parking Area, make your way over the footbridge spanning the Firehole River and continue hiking along the old road past springs and thermal pools—the path is wide and flat, making for an easy trek through the Midway Geyser Basin.

After hiking 0.6-mile, watch for the Overlook Trail—the trail will be on the left side of Fairy Falls Trail, leading uphill. The trail ascends 105 feet over 0.2-mile to reach a viewing platform with exceptional views of Grand Prismatic, Excelsior Geyser, and the Midway Geyser Basin.