National Park & Nature

Grand Prismatic Spring

📍 Grand Prismatic Spring, Yellowstone National Park, WY 82190, USA

1 photos

4.8/ 5.0

★★★★★

Quick Facts

Location: USA, Wyoming
Category: National Park & Nature
Duration: 2-3 hours including the overlook trail
Opening Hours: Open year-round; from mid-December to late March the road is open only to oversnow travel (snowmobiles/snowcoaches) - cars cannot reach it
Ticket Price: Adult: Free · Covered by Yellowstone entry: USD 35/vehicle 7 days, USD 30 motorcycle, USD 20/person on foot (under-16 free). Non-US residents 16+ add USD 100 from 2026; annual pass exempt.
Address: Grand Prismatic Spring, Yellowstone National Park, WY 82190, USA
Coordinates: 44.5251, -110.8382

Introduction

Grand Prismatic Spring sits in the Midway Geyser Basin of western Yellowstone National Park, Wyoming. About 90-110 m across and 50 m deep, it is the largest hot spring in the United States and the third largest in the world, after New Zealand's Frying Pan Lake and Dominica's Boiling Lake. The center runs about 70 C and, being too hot for life, glows a deep sapphire blue; outward, cooling water supports bands of heat-loving microbes that paint green, yellow, orange and red rings around it. The colors shift with the seasons - orange-red in summer, dark green in winter. Fur trappers noted a boiling lake here in 1839; Hayden's 1871 survey named it for its prismatic colors, and the expedition's paintings helped inspire the world's first national park. From the boardwalk you see it up close through the steam; from the Grand Prismatic Overlook Trail, a 1-km climb from the Fairy Falls parking lot, you take in the whole glowing disc at once.

✨ Highlights

Rainbow rings

From the deep blue center to rust-red margins, colored bands produced by heat-loving microbes at different temperatures; brightest under midday sun.

World's third largest

About 90-110 m across and 50 m deep - the largest hot spring in the US and third largest worldwide, after New Zealand's Frying Pan Lake and Dominica's Boiling Lake.

Overlook trail

Climb about 1 km (105 ft) from the Fairy Falls parking lot to the Grand Prismatic Overlook for a full view of the spring and Midway Geyser Basin.

Discovery history

Fur trappers noted a boiling lake here in 1839; Hayden's 1871 survey named it for its prismatic colors, and the expedition's paintings helped create the world's first national park.

Seasonal colors

Mats turn orange-red in summer and dark green in winter as chlorophyll-to-carotenoid ratios shift with light and temperature.

Excelsior Geyser next door

In the same basin, this crater is 91 m long with water near 93 C, dumping 4,000 gallons a minute into the Firehole River - once Earth's mightiest geyser.

🛈 Practical Info

→Best time：After 10 am and before 4 pm the steam thins and midday sun brings out the colors; early mornings are often steam-blanketed.

→Overlook trail：Do the Grand Prismatic Overlook Trail (1.9 km round trip, 32 m climb, 1-2 hrs) from the Fairy Falls lot; the boardwalk alone gives a ground-level view only.

→Parking：The Fairy Falls lot is tiny and fills by 9 am in peak season; tour the boardwalk first and return later for the overlook.

→Safety：Stay on boardwalks and trails at all times - the crust is thin and thermal water can kill; no pets on the trail.

→Combine with：Midway Geyser Basin sits on the lower loop, 2 miles from Old Faithful, easy to pair with West Thumb and Madison.

→Worth it?：Yes - Yellowstone's top photography icon, but the postcard view exists only from the overlook; budget 1-2 hours for the trail, not just the boardwalk.

→Watch out：Judging the spring from ground level will disappoint - steam and flat light mute the colors; from roughly December to March the road is open only to snowmobiles and snowcoaches.

→Opening Hours：Open year-round; from mid-December to late March the road is open only to oversnow travel (snowmobiles/snowcoaches) - cars cannot reach it

→Transportation：By car

Ticket Information

Ticket Information
Adult	Free

Covered by Yellowstone entry: USD 35/vehicle 7 days, USD 30 motorcycle, USD 20/person on foot (under-16 free). Non-US residents 16+ add USD 100 from 2026; annual pass exempt.

💡 Tips

• Steam thins after 10 am and midday sun saturates the colors; a polarizer helps cut glare.

• The overlook hike is 1.9 km round trip with 32 m of climb - 1-2 hours, easy, no pets allowed.

• The Fairy Falls lot is tiny; arrive before 9 am and never park on the roadside when it is full.

• Do both the boardwalk and the overlook: close-up texture and steam versus the full rainbow disc.

• Don't skip Excelsior Geyser Crater in the same basin - 91 m long, water near 93 C, steam everywhere.

• In winter (roughly December to March) you must go by snowmobile or snowcoach; check oversnow operations first.

FAQ

What are the opening hours of Grand Prismatic Spring?

Open year-round; from mid-December to late March the road is open only to oversnow travel (snowmobiles/snowcoaches) - cars cannot reach it

How much is the admission for Grand Prismatic Spring?

Adult: Free; Covered by Yellowstone entry: USD 35/vehicle 7 days, USD 30 motorcycle, USD 20/person on foot (under-16 free). Non-US residents 16+ add USD 100 from 2026; annual pass exempt.

Any practical tips for visiting Grand Prismatic Spring?

Steam thins after 10 am and midday sun saturates the colors; a polarizer helps cut glare. The overlook hike is 1.9 km round trip with 32 m of climb - 1-2 hours, easy, no pets allowed.