Hiking the Midway Geyser Basin Trail (Grand Prismatic Spring) in Yellowstone National Park
Distance: 0.7 miles / 1.1 km
The Midway Geyser Basin Trail, more commonly called the Grand Prismatic Spring Trail, in Yellowstone National Park is a very short and easy day hike along a series of boardwalks past the stunning and world-renowned Grand Prismatic Spring!
This is the spring that is famously shot from above and commonly seen on book covers, postcards, and the like in general stores across Yellowstone National Park!
Now, it’s very important to mention that the Midway Geyser Basin Trail is not the best place to see the Grand Prismatic Spring. That is reserved for the Grand Prismatic Overlook Trail on the hillside above the spring in the photo below.
That said, I recommend hiking both if you’re visiting Yellowstone for the first time, as there is something very unique about seeing the Grand Prismatic up close on the boardwalks, as well as catching it from above, which is the best way to see the colors without booking a helicopter tour out of West Yellowstone!
Midway Geyser Basin Trailhead Parking
Parking for the Midway Geyser Basin Trail is located in a very small parking lot directly off Grand Loop Road, between Fairy Falls to the south and Fountain Flats Drive to the north.
That said, I want to highlight the words "very small," as the Midway Geyser Basin Trailhead has one of the smallest and most competitive parking lots in Yellowstone National Park and is even the root cause of daily traffic on this stretch of Grand Loop Road during the busy summer travel season.
Those who work in the park have even told me they try to avoid driving in the area during the mid-morning and early afternoon hours because traffic can back up for miles in either direction.
What all this hopefully says is that it’s best to arrive early, meaning sunrise! This is because, by around 7:30–8:00 a.m., a line has typically formed for the parking lot on most nice summer days.
Google Maps Directions: Midway Geyser Basin Trailhead (Grand Prismatic Spring)
Hiking Checklist - Yellowstone–Tetons
Here is a complete list of must-have things that you will want for any hike in the Yellowstone–Teton area.
Hiking the Midway Geyser Basin Trail
Firehole River
The Midway Geyser Basin Trail begins on a bridge across the Firehole River, followed by a short, gradual ascent to the start of the scenic loop.
Immediately on the other side of the river, the Midway Geyser Basin Trail climbs the one and only hill on the entire hike.
This is where the Midway Geyser Basin Trail levels out at the top of the hill, meaning the rest of the hike around the loop just ahead is entirely flat.
Midway Geyser Basin Loop Trail
After just 0.2 miles (0.3 km), the Midway Geyser Basin Trail reaches the start of the short 0.3-mile (0.5 km) loop through the basin.
Once here, go left, as the National Park Service manages the trail as a one-way loop since there is so much foot traffic throughout much of the year.
Excelsior Geyser Crater
The Excelsior Geyser is the first thermal feature passed on the Midway Geyser Basin Trail.
According to the National Park Service and the USGS, eruptions are very violent but entirely unpredictable.
Excelsior Geyser was originally named "The Cauldron," but following extraordinarily violent eruptions during the park’s early history, Yellowstone’s second superintendent, Philetus W. Norris, thought the dramatic eruptions deserved a more extravagant name—hence "Excelsior," which it has been known as ever since!
After the Excelsior Geyser, the Midway Geyser Basin Trail turns west and starts heading directly toward the Grand Prismatic Spring.
Grand Prismatic Spring
This is the far western end of the Midway Geyser Basin Loop, and it’s where the trail starts paralleling the Grand Prismatic Spring for the first time!
That said, the trail, at its closest point, is roughly 55 ft. (16.8 m) from the edge of the spring, which is both because of the extremely thin crust and fragile bacterial mats that give the Grand Prismatic its vibrant colors around the perimeter and because of litter/ vandalism.
It doesn’t seem to matter how many signs the National Park Service posts, visitors constantly disrespect the thermal features across Yellowstone National Park. Please don’t be a part of the problem!
As for the Grand Prismatic itself, it is the largest hot spring in Yellowstone National Park, at roughly 330 ft. (101 m) across at its longest point!
Warning
This shouldn’t need to be said, but please do not leave the boardwalk!
In fact, the U.S. Department of Justice prosecutes these offenses very aggressively, which often results in short prison sentences, fines, and even supervised release.
I’m not kidding! There are countless examples of visitors leaving the boardwalk, both here at the Grand Prismatic Spring and across Yellowstone National Park, and all who were caught and identified have faced serious legal consequences. Here are a few examples:
June 18, 2020: Two Pennsylvania women received a two-day jail sentence and fines for leaving the Midway Geyser Basin Trail.
June 13, 2024: A Washington man was sentenced to seven days in jail and fined for leaving the boardwalk in Norris Geyser Basin.
April 9, 2026: A Texas man was sentenced to five days in jail for walking on thermal features at Mammoth Hot Springs.
I could go on, and you may even remember the two tourists who famously walked across the Grand Prismatic bacterial mats in the summer of 2026, an incident that went viral across the news and social media!
Beyond leaving the boardwalk, the next most common offense is visitors flying drones, which is illegal in all U.S. National Parks—and sadly, there is a crashed and unrecovered drone in the Grand Prismatic Spring.
Please be a responsible visitor!
Do You See It?
Yes, these are Grizzly tracks in the bacterial mats surrounding the Grand Prismatic Spring!
The way you can tell they are Grizzly tracks and not from a Black Bear is that the toes from the front paw (the smaller tracks) follow a straight line across the bottom, whereas a similar line drawn across a Black Bear’s front paw would intersect the outer two toes because they are more rounded.
This is the closest the Midway Geyser Basin Trail gets to the edge of Grand Prismatic Spring, roughly 55 ft. (16.8 m) away.
After the closest point, the Midway Geyser Basin Trail turns sharply back toward the trailhead, where it passes two more thermal features before completing the short loop.
Opal Pool
Opal Pool is a small hot spring and the second-to-last thermal feature on the Midway Geyser Basin Loop.
As previously mentioned, this is exactly where one of the cases cited above occurred, when the two women from Pennsylvania left the boardwalk and were prosecuted for damaging the bacterial mats surrounding the thermal hot spring.
Turquoise Pool
Turquoise Pool is the final thermal feature on the Midway Geyser Basin Trail before the loop returns to the beginning.
According to the National Park Service, Turquoise Pool is also a small hot spring, similar to Opal Pool, and measures roughly 100 ft. (30.5 m) across, or almost exactly one-third the size of the Grand Prismatic Spring!
Midway Geyser Basin Loop Junction
This is where the Midway Geyser Basin Trail completes the short 0.3-mile (0.5 km) one-way loop and returns to the initial junction.
That said, go left at this split to return to the trailhead off Grand Loop Road.
On a different note, it’s very common to try to visit multiple geyser basins in the area in one day, but if you happen to get done with the Midway Geyser Basin hike around 8:00 a.m. or later, I would consider saving other popular trailheads, like Fairy Falls and the Fountain Paint Pot Trail, for another day, as they are far less enjoyable when they get busy early in the morning during the summer.
Old Faithful (Upper–Lower Geyser Basins)
Canyon Village
Maddison–Norris
Yellowstone Lake & East Entrance
Mammoth, Lamar Valley & Tower
